II. INTERNATIONAL SYMPOSIUM

1 I N I S - m f - - 1 1 2 3 3

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CHEIATINGAGENTS

IN^PHARMACOLOGY, TOXICOLOGYAND THERAPEUTICS

PILSEN. 12 14 8 1987

2nd International Syaposiua

CHELATING AGENTS IN PHARMACOLOGY, TOXICOLOGYAND THERAPEUTICS

Pilsen, 12.-14. 8. 1987

organized byTHE CZECHOSLOVAK NEOICAL SOCIETY J.E.PURKYNt

The Czechoslovak Pharmacological Societyin cooperation with

THE DEPARTMENT OF PHARMACOLOGYFaculty of Medicine, Charles University

PilsenTHE INSTITUTE OF HY6IENE AND EPIDEMIOLOGY

Prague

OrganizingV. Eybl0. MaitzoviD. CaisoviM. CikrtM. KoutenskiJ. Koutensk?J. SykoraA. Zechaeister

CoeaitteePresidentSecretaryMeabera

B

This volume contains all abstracts ofpapers accepted till 15th April 1987by the Organizing Committee. Theseabstracts are photographically repro-duced from the original forms submittedby the authors. The authors are responsiblefor the content and the grammatical styleof their abstracts.The papers are arranged in alphabeticalorder of the authors names.

\

O R A L C O M M U N I C A T I O N S

EFFECTS OF COMPLEXING THIOLS ON BILIARY EXCRE-TION OF LEAD IN THE RAT

J.ALEXANDER, J.AASETH

Department of Toxicology, National Instituteof Public Health, Geitmyrsvn. 75, 0462 Oslo 4,Norway," Hedemark Central Hospital, Elverum,Norway

The fecal route is an important excretory path-way for lead in humans, and may as in the ratbe derived from biliary excreted lead. Previousstudies indicate that lead is excreted into bi-le by a glutathione dependent mechanism (Ale-xander et al.). The efficiency of therapeuticchelating agents may in addition to enhancedurinary metal excretion also work via an en-creased biliary excretion. Several chelatingagents were therefore examined: diethyldithio-carbamate (DDC) BAL, DMSA, N-acetylpenicillami-ne and penicillamine. DDC initially inhibitedbiliary lead excretion while all of the other Jcompounds caused an increased biliary lead ex- jcretion in lead exposed rats. Penicillamine 1was the most efficient compound. Their media- ;nism of action is not clear as their effects .<may either be a result of lead-complexation hwithin the cell followed by excretion of thecomplex or indirectly by influencing glutathio-ne metabolism. Increased levels of glutathionein the liver may cause an enhanced lead excre-tion into bile. To prevent reabsorption of bi-liary excreted lead in the gut it is suggestedto combine treatment with penicillamine with anonabsorbable lead chelating agent.

Alexander,J., Aaseth, J. and Mikalsen, A. ActaPharmacol. Toxicol. Suppl. 59, 486-489, 1986.

CHELAT1ON OF CADMIUM IN VIVO.

Oie AndersenDepartment of Environmental Medicine, Odense University,3.B. Winsl#ws Vej 19, DK-5000 Odense C, Denmark.

Acute human Cd intoxication is always due to oral or pulmonaryexposure, and immediate mortality is caused by gastrointestinal(g.i.) or pulmonary epithelial damage. However, secondary hepaticand renal damage may develop. The acute toxicity of Cd and effectsof chelators thereon has mainly been studied experimentally afterparenteral exposures, where acute mortality is due to hepaticnecrosis. The present work demonstrated that chelating agents couldaffect the acute toxicity of cadmium quite differently depending onthe administration route of both cadmium and chelator. The bestexample is DDC, which after parenteral administration of both DDCand cadmium is an efficient antidote, but which after oral admini-stration of cadmium increased the acute toxicity of cadmium quitedramatically. Effects of chelators on acute cadmium toxicity wasinvestigated after either oral or intraperitoneal (ip) exposure to bothchelator and cadmium. After comparing effects of about 20chelators, including a number of polyaminopolycarboxylic acids andvarious derivatives of BAL, DDC and penicillamin, DMSA was foundto be superior after oral exposure, while TTHA was superior after ipexposure. Both reduced the retention of cadmium efficiently, andthey acted synergistically when administered together (DMSA orallyand TTHA ip) 15 min after a highly toxic oral dose of cadmium. Ourresults corroborate and extend those of Mark Jones and define avery effective chelation antidote treatment of oral cadmiumintoxication, which also minimize cadmium retention and thus therisk of secondary systemic toxicity.

METABOLIC STUDIES OF MESO-DMSA IN HUMANS

I k VASKEN APOSHIAN, RICHARD M. MAIORINO AND DANA F . PERRY

University of Arizona, Tucson, Arizona, USA

The presence of oxidized species of meso-2,3,-dimercap-tosuccinic acid in human urines has been determined andquantified. Unaltered DMSA was determined by derivatizationof the thiol groups with monobromobirnane (BB). Total DMSA(unaltered and altered) was determined by electrolyticreduction followed by BB derivatization. The bimane deriva-t ives were ident i f ied and quantified by HPLC andfluorescence. Six male human volunteers were given lOmgDMSAAg po after which their urines were collected during a14hr period. At the time of writing of this abstract,s tudies of the urine of three volunteers have beencompleted. The unaltered DMSA excreted in the urine 14 hrsafter DMSA administraton averaged 2.62% of the given dose;the altered DMSA was 20.98%. The peak of excretion ofunaltered DMSA and altered DMSA occurred at 2 hrs and 4 hrs,respectively. Based on human and rabbit studies, the *

altered DMSA consists of disulfide and tetrasulfide forms of 5DMSA. The urines are also being analyzed for Cu, Zn and Pb {content. These new methods for the determination of the cdithiols and their oxidized forms should lead to a better iunderstanding of the metabolic properties of these \increasingly important, orally effective metal mobilizingagents.

EFFECT OF DMPS AND D-PENICILLANINE ON THE LEVEL OF

LIPID PEROXIDATION PRODUCTS IN FiETAL-POI SONED RATS

L.BENOV, O.PIONOUICH, I.BENCHEV

Department of Biophysics, University School of

Medicine, 5800 Pleven, Bulgaria

The level of lipid peroxidation prooucts (con-

jugated diens, lipid hydroperoxides, fluorescence

products and malondialdehyde) and the activities

of some enzymes protecting the cell against activa-

ted oxygen have been studied in copper and mercury

poisoned rats, treated with 2,3-dimercapto-1-pro-

pane sulfonic acid (DFIPS) or D-penicillamine (DP).

It has been found that both thiols significantly

inactivated superoxide dismutase in blood, liver )

and kidney in healthy as uell as in metal-poisoned ]

rats. The treatment of copoer-poisoned rats with :

DMPS or DP caused increase of ("IDA and fluorescence 5,

products in the blood. In the liver, houever, DP

afforded protection against lipid peroxidation but

DHPS did not. Decrease of the level of the lipid

peroxidation products has been observed also in the

liver of mercury-poisoned rats treated with DPIPS

or DP. Neither of the antidotes exerts effect on

the level of the lipid peroxidation products in

the kidney.

10

CANCER PREVENTION BY CHELATION THERAPY

W.BLUMER

General Practice, Netstal, Switzerland.

The cancer mortality among 331 adult persons livingadjacent to an automobile road was found to be 9times higher than in a traffic-free section of thesame town. The inhabitants residing near the road hadsuffered also very often from haedaches, fatigue,stomach ailments, depressive conditions, nervous trou-bles and tablets-misuse. The existence of small leaddeposits as well as the healthimpairing effect of leadwere demonstrated by measurements of lead and delta-aninolaevulinic acid in urine. After treatment withCalcium-Dinatrium-EDTA in order to eliminate lead thepatients were cured and the lead content as well asthe amount of deltaaminolaevulinic acid became normal.59 of the residents nead the road had been treated inthis way. Only one of these later died of cancer. Of172 persons, who were not treated, 30 died of cancer,or ten times more percentage-wise. The concentrationsof airborne lead and carcinogenic hydrocarbons insedimented dust and in suspended dust were much grea-ter along the automobile road than in the traffic-free section. These findings together with many otherreports in the medical literature lead to the suspi-cion that lead in gasoline, combined with othercarcinogenic substances in automotive exhaust gases,increases the incidence of cancer.

11

CHELATION THERAPY IN OCCLUSIVE ARTERIOSCLEROSIS0. BRflCKNEROVA

3 Internal Clinic, Purkyni University, Brno,CSSR

In the course of the last 20 years fleJSDTAwas applied in i.v. drop Infusions to a groupof 65 patients( 51 men + 14 women) sufferingfrom ocelusive arterial disease of the lowerextremities. Each infusion contained 3 gme ofKa9EDTA (CHELATON III) dissolved in 500 ml of5% fructose and lasted about 4 hours.Each cure consisted of 30 Infusions, one dai-

ly, for 5 day8''each week. The whole cure lasted6 weeks. In some patients the therapy waa repe-ated after a pause of 6 months.At the beginning of treatment the average age

was 54 in men and 63 in women. In most of thepatients multiple atherosclerotic lesions werepresent not only in the arteries of the limbsbut also in the coronary and/or cerebral arte-ries* This limited the chance of surgical recon-struction*The therapy was well tolerated and an amelio-

ration waa achieved namely in prolongation ofthe walking distance in stage II ( Fontaine)andthe disappearance of rest-pain in stage III* Instage IV the results were less favourable. Afterlong-term observation 34% of the group are ali-ve, 51% died and 15% are loat of evidence.The mechanisme of action is explained by some

authors by disintegration of atherosclerotic pla-oues and elimination of metastati.s caloiua framdeposits which in not accompained by ceteoporo**.sis.

12

OBJECTIVE EVIDENCE OF THE EFFICACY OF CHELATION THERAPYBY RAOIONUCLIOE STUDIES IN PATIENTS WITH HEART AND BRAINDISORDERS.H.R. Casdorph, M.D.,Ph.D., Casdorph Cinic, Long Beach, CAUSA

Eighteen patients with documented Atherosclerotic HeartDisease were studied using .Technetlun 99a tomeasure lefc ventricular ejection fraction at rest beforeand after the administration of 20 treatments of EDTAChelation Therapy. A s t a t i s t i c a l l y s ignif icantimprovement in the left ventricular ejection fractionQccured in the treated group of patients.

The ejection fraction increase In 17 of the 18 patientsfollowing the series of IV Infusions of 3 grams EDTA.The itean change was +5.77Z (P is greater than 0.0005).

EDTA is known to bind or chelate calcium «s well as otherMinerals In the body. It is been shown to remove calciumparticles deposited in the arterial wall, plaque and *athromas. ]

IIn a second study of 15 patient with a variety of brain ':disorders, an indirect method for measqr^ng cerebral >blood flow utilizing Techne.tium 99m was utilized. One \patient age 51 had the diagnosis of Schizophrenia,. 4 jpatient has CT scan evidence of Cerebral Atrophy with the <diagnosis of Alzheimer's' Disease and the remaining 10 hadvarious manifestation of Cerebro-Vascular Disease.

In al l IS patients, the cerebral blood flow was abnormalbefore the i n s t i t u t i o n of Chelation Therapy. Followingthe 20 IV Chelation Treatments, the cerebral blood flowstudy was repeated with Technetlu.re 99m. A highlysignificant improvement in cerebral blood flow occuredfollowing the intravenous Infusion of dlsodlum EDTA.

13

EFFECTIVENESS OF INTRAVENOUS EDTA CHELATIONTHERAPY FOR ATHEROSCLEROSISE . M . C R A N T O NMount Rogers Clinic, Trout Dale, Virginia 24378, USA

Intravenous EDTA chelation therapy has been utilized for more than 3decades in the treatment of atherosclerotic cardiovascular disease. All pub-lished data are positive and fully support lasting clinical effectiveness of chela-tion therapy for atherosclerosis, despite opposing editorial comment from thosewith vested interests in bypass surgery and related procedures. Benefit com-monly persists for months or years. Kitchell, Meltzer, et al, published a scriesof favorable reports, but in 1963 they published a negative conclusion to theirfinal paper which was contrary to their very positive data. After eighteenmonths following approximately 20, 3.0 gram infusions of EDTA, 28 of 46cardiac patients remained clinically improved. Several recent studies confirmthose earlier reports.

In 1981, Casdorph utilized isotope studies to measure improvement in theejection fraction of 17 out of 18 cardiac patients (P<0.001), following 20, 3.0gram infusions of EDTA. Casdorph also reported increased cerebral blood flowin 14 out of 15 patients with cerebrovascular disease (P<0.001), followingfrom 13 to 26, 3.0 gram EDTA infusions. In 1982, McDonagh. et al, utilized anoculocebrovasculometric method, based on tonometric measurement of intrao-cular arterial pressure, to document improved ccrebrovascular blood flow in 57patients with arterial disease. Following 28, 3.0 gram infusions of EDTA, amean improvement of 18% in cerebrovascular arterial stenosis was reported(PO.001). In 1985, McDonagh, et al, studied 77 elderly patients with a total of117 legs afflicted by arterial stenosis. Following 26, 3.0 gram infusions ofEDTA, a 22% average improvement in the ankle/brachial Doppler systolicblood pressure ratio, from 0.77 to 0.94, was reported (P<0.001). Other symp-toms, not directly related to the cardiovascular system, have also been observedto improve. McDonagh measured improvement in many such symptoms fol-lowing 26, 3.0 gram infusions of EDTA. Using the Cornell Medical IndexHealth Questionnaire, a 15% average improvement was reported in the follow-ing organ systems: musculoskeletal, neurological and cardiovascular (P<0.001);respiratory (P<0.010); gastrointestinal (P<0.025); and ur^ary (P<0.050). Inthe area of cancer prevention, Blumer and Reich reported ..n IS-year study inwhich mortality from all types of cancer in a grcup of 59 chelated patients wasonly 10% (90% less) than among 172 matched control subjects,Cranton EM, Frackelton JP: Free radical pathology in age s«bocis'.ed cisieavet: Treatment withEDTA chelation, nutrition »nd antioxidanti. / Holistic MetllW4sfi{\):t>-97.

14

THE INVESTIGATION OP COMPLEX FORMATION US THESYSTEMS FeCl, - CuCl2-PYRID0XAL - GLUCOSAMINE

WITH THE MATHEMATICAL MODEL METHOD.

DOBRYKIRa. N.A. .AGRAHOYITH A.M..ISAEVA B.V..

MARTYNENKO L.I.

Moscow State University,MoscowtUSSR

The data of pH-metric titration at 25°in 0,154

mol dm*"* KaCl (physiological solution) the sys-

tems FeCl,- CuCl2 - pyridoxal(HPal)-glucosamine

(Gl) were treated with mathematical model method.

The correct model was chosen and the square sum

was taken as the first criterion. It was found

that the best models comprise following complex

forms (with respective formation constants):

CuPalOH (11,61), FePal (9,90), Fe(PalOH)(2O,53),

FePal(0H)2 (28,9O),CuGl O,54-),CuGl0H(11,56),

CuGl(0H)2 (18,50), CUG1 2(0H; 2(20,96), FeGlOH

(19,15), FeGl(0H)2 (3O,O5),CuPalGl (11,13),

Cu(PalGl)0H(18,30),Fe(HPalGl)(22,3O),Fe(PalGl)

18,80.

These data are useful for recognize the me-

chanism of the action some copper- and pyrido-

xal—depending enzymes.

15

CHELATING AND ANTIOXIDANT EFFECTS OF RUTIN ON LIPIDPEROXIDATION IN LIPOSOMES AND MICROSOMES

A.I.DOROZHKO, A.V.BRODSKII, and I. B. AFANA.S ' EVAil-Union Vitamin Research Institute, Moscow, USSR

Rutin (a flavonoid possessing P vitamin activity)2+

effectively inhibited the Fe -initiated lipid per-

oxidation in lecitin liposomes and bovine heart micro-

somes (Ig0=l-10~ M). It was also showed that rutin

readily formed the stable Fe(II)(rutin)„ complex with

maxima at 255, 280, and 420 run (differential spect-

rum) in the phosphate buffer.

We concluded that the inhibition of lipid peroxi-2+dation by rutin is due to both its bonding Fe ions

and its antioxidant action. The contribution of each2+mechanism depends on the Fe /rutin ratio, pH, etc.

We found that rutin reacts directly with O* in

aprotic media to form an intermediate with a maximum

at 450 run.

In the presence of ascorbic acid rutin additively

inhibited lipid peroxidation. But at small concentra-

tions of ascorbic acid (when the latter behaves as a

prooxidant) rutin and ascorbic acid were antagonists.

It was concluded that in Fe (II)(rutin)„ Fe2+ is

not able to initiate lipid peroxidation, whereas ru-

tin retains its antioxidant properties. These find-

ings can be of importance for using rutin as a drug.

16

POSSIBLE THERAPEUTIC VALUE OF INTRAVENOUSHYDROGEN PEROXIDE

C.H. FA'RR, ft.P., Ph.D.

Intravenous EDTA Chelation Therapy (CT)removes divalent cations which reduce catalyzedfree radical production and improves circulationto increase tissue oxygenation. Studies ofintra-arterial and intravenous infused Hydrogenperoxide (H202), a free radical intermediate,have shown it to have therapeutic value inregional hypoxia and cardiovascular disease.H202 is rapidly reduced to H20 and 02 bycatalase. The 02 produced was thought to bedissipated through the lungs and has no systemiceffect. Other studies indicate a complex isformed between H202 and cytochrome-c whichexists 30 minutes. We measured expired oxygenin normal subjects, ages 28 to 67, receiving IVinfusions of 100 mL to 250 mL 0.15% bufferedH202 in 5% dextrose in water. Oxygenconsumption measurements recorded a 100%increase in metabolic rate due to stimulation ofmitrochrondrial oxidative enzyme systems.During these same infusions, peripheral dilationoccurred and skin temperature increased. Over200 IV infusions of H202 have been withoutsystemic side effect. Inflammatory reaction atthe injection site is prevented by pre-infusionwith heparin. The therapeutic value of thisphysiological action of H202 is beingin ve s t iga ted.

17

fc

LACK OF EFFECTIVENESS OF D-PENICILLAMINE IN ACUTE EXPERIMEN-TAL ARSENIC POISONING

B. FICHTL, H. KREPPEL, F.X. REICHL, W. FORTH

Walther-Straub-Institut fur Pharmakologie und Toxikologie,Nussbaumstr. 26, 8000 Miinchen 2, FRG

Based oa some anecdotal case reports D-penic.iiJ.amine (DPA)has been advocated for the treatment of arsenic poisoning.Experimental evidence, however, supporting that recommenda-tion is lacking. In the present experiments the effective-ness of DPA was compared with dimercaprol (British Antilewi-site; BAL), dimercaptopropanesulfonate (DMPS), and dimercap-tosuccinic acid (DMSA) using different controlled experimen-tal settings.Mice an^ guinea pigs were injected s.c. with 8.4 mg /kgAs?0« (containing a tracer dose of As). 30 min later 0.7mmol/kg of DPA or one of the other antidotes was injectedi.p. As determined four hours-rafter the arsenic injectionDPA was unable to reduce the As content in any of the or- )

gans investigated (blood, liver, kidneys, lungs, heart, tei>- i;tes, spleen, skeletal muscle, and skin). On the other hand, fBAL, DMPS, and DMSA markedly reduced the tissue content of J,As with respect to controls* ••

The ability of the antidotes to reverse biochemical effects »of arsenic was investigated in vitro using suspensions of ')incubated renal tubulus cells. The marked inhibition of glu- jconeogenesis induced by 30umol/l As?0_ was almost completely jreversed following addition of 90 umol/1 of either BAL, DMPS !.or DMSA. In this experimental model,too, DPA was ineffective. !The present results are in line with previous reports that !BAL, DMPS, and DMSA are highly effective in protecting expe-rimental animals against the lethal effects of arsenic (Krep-pel and Szinicz, Arch.Pharmacol. 332:R27, 1986) whereas DPAis devoid of such action (Aposhian, Toxicol. Appl. Pharma-col. 61:385, 1981). It is concluded that the use of DPA inacute arsenic poisoning needs to be reevaluated.

18

LONG-TERM TREATMENT OF LEAD (Pb) POISONING WITH DIMERCAPTOSUC-CINIC ACID (DMSA). H.L. Haust. J.D. Spence. H. Poon. F. PeterDepts. of Biochemistry and Medicine, Univ. of Western Ontario;Children's Psychiatric Research Institute and Victoria HospitalCorporation, London, Ontario, Canada.In a 41 year old man with a drastic Pb burden, tine efficacy

and safety of U S A was ascertained during its daily oral admin-istration in 3 divided doses for periods up to 30 days. In atypical treatment schedule, DMSA, 30 mg/kg/day was given forthe first 7 days. The dose was then tapered via 25 mg/kg/dayand 20 r^/kg/day (days 8 and 9) to 15 Tog/kg/day (days 10-23 =DMSA maintenance period).Within the first 6 days, blood Pb fell from 120 to 25 ug/dL

and red oell aminolevulinic acid dehydratase (ALA-D) activityincreased from 9 to 285 nmol porphobilinogen/L/s. Blood Pbther increased and levelled during the EMSA maintenance periodat values not exceeding 53 yg/dL. Pre-DMSA urine Pb was 879ug/day. During the first 9 DMSA days, a total of 44 mg of Pbwas eliminated via urine. During the remaining 14 DMSA days,the total urinary Pb output yielded 37 mg. On DMSA day 2, ALAand coproporphyrin in urine had fallen precipitously to sus-tained normal levels from pre-treatment values of 54 mg/dayand 2054 yg/rtay, respectively. Throughout the DMSA maintenanceperiod, ALA-D activity in red cells was once more subnormal,contrasting with normal levels for ALA, its substrate, as mea-sured in urine. This indicates that Pb present in soft tissuessuch as liver and kidney was chelated by DMSA more effectivelythan Pb located in the erythron. Iron administration through-out the IWSA maintenance period was well tolerated and entaileddiscernible increases in haemoglobin, haematocrit, MCV and re-ticulocytes. Reversible DMSA side effects included minor in-creases in urine Zn, Cu and Mg and in serum GOT (AST), GPT(ALT), total cholesterol and triglycerides. Transitory decrea-ses in HDL cholesterol were confined to the first 5 DMSA days.It is concluded that treatment of Pb poisoning with DMSA as

the sole chelant can be adjusted to the severity of the indivi-dual case and offers advantages over its treatment with conven-tional chela ting agents such as CaNa^EDTA, BAL and penicillam-ine.

19

v

I

EFFECT OF DMPS AND DMSA ON LEAD-INDUCED LIPIDPEROXIDATTON IN RAT LIVER AND KIDNEY

S.GABOR. M.BOTOC, A. KOVATS

Institute of Hygiene and Public Health, Cluj-Napoca, Romania

We have investigated the reversal by DMPSand DMSA of lipid peroxidation in lead-treatedanimals. Male rats were given intraperitoneallytwo doses of lead acetate-20mg/kg and lOOmg/kgb.w., daily, for six days. DMPS and DMSA in do-ses of 50 /imoles/kg b.w, were injected immedia-tely after lead application. The liver and kid-ney of sacrified animals were examined for li-pid peroxide concentrations using TBA-reaction;lead was measured by AAS. Both doses of leadcaused a significant increase of lipid peroxi-des in non-treated with chelators animals, com-pared to control group. The metal mobilizingeffect achieved by DMPS and DMSA paralleled thesignificant decrease of lipid peroxide contentin liver and kidney. According to our results,lipid peroxidation is proposed as a possible me*chanism of lead toxic effects upon liver andkidney.

20

INTERACTIONS OF MES0-2,3-DIMERCAPT0SUCCINIC ACID(DMSA) WITH DIALKYLTIN COMPOUNDS

6. HENNIGHAUSEN, 3. MERKORD and G. KRDNING

Institute of Pharmacology and Toxicology, Wilhelm-Pieck-University, Rostock, GDR

Quality and quantity of toxic affects of dialkyl-tin compounds are dependent on the length of thealkyl chains. In mice and rats dialkyltin com-pounds with alkyl chains of 4 - 6 C-atoms induceddamages of bile ducts, liver and thymue,associated with biliary excretion of high concen-trations of organotin. DMSA diminished theseorganospecific toxic effects and the biliaryexcretion of organotin. The toxic effects ofdialkyltin compounds with alkyl chains of 7 and 8C-atoae on the thymus ware not affected by DMSA.In vivo there was no difference in the antago-nistic activity of DMSA to the toxic effects ofdibutyltin dichlofi.de (DBTC) and dibutyltin sul-fide (DBTS). In vitro DMSA increaeed theinhibition of 6SH-S transferases by DBTC, whereasthe inhibitory activity of DBTS was not affected.In comparison to 2,3-dimercapto-l-propanol, DMSAshowed a higher antidotal activity in acuteintoxicationa of mice and rats with DBTC,

21

New Chelating Agents for Detoxication of Metal

Poisoning

Hsieh Yu Yuan Chen Wen Zhi

Shanghai Institute of Materia Medica, Academia

Sinica

A Series of polyphenolic aminopalycarboxylates

of general formula CD was synthesized by a Mannich

reaction of 3,4-dihydroxybenzoic acid with formalde-

hyde and Iminodicaetic acid and subsequent trans-

formation into their corresponding amides.

TTHO- ^ "'I COOH

C H2 Nx INCH CONHR' •]

These compounds were tested on rats intoxicated r

with uranyl acetate and four of them demonstrated \

better results in enhancing the excretion of uranyl f

ion than those well known chelating agents as tiron

and phosphicine. This type of compounds revealed I

suitable characteristics for chelating agents as ',

they form complexes of low stab ) fv constants j

with alkaline earth metals while ^ :•<• -a t • rvith most :

metals as Mn , Cd , Co , Ni , Cur , l0o and

Fe with rather high stabilities.

22

ORALLY ACTIVE a-KETOHYDROXYPYRIDINE IRON CHELATORS INTENDED FORCLINICAL USE.

GJ KONTOGHIORGHES

Department of Haematology, Royal Free Hospital, Pond Street,LONDON NW3 2QG, ENGLAND.

Several a-ketohydroxypyridine iron chelators have been des-igned to be used for the treatment of iron overload and toxicity.Five of these chelators have been identified to be promisingfor a clinical trial using the following screening system a)iron mobilisation in vitro from iron containing proteins namelytransferrin, lactoferrin, ferritin and haemosiderin; and invivo from mice, rats and rabbits by parenteral and intragastricadministrations b) toxicity tests in cells in culture and in amodel of iron induced free radical damage and c) structure/ironbinding activity/toxicity correlation.

From these five chelators namely 1,4-dihydroxypyrid-2-one,1-ethyl-3-hydroxypyrid-2-one, 1-methyl-, 1-ethyl- and 1-propyt-2-methyl-3-hydroxypyrid-4-ones the last three have been shownto be the most effective in increasing iron excretion whenadministered orally (200mg/kg) to animals, to levels equal orhigher to those caused by parenteral desferrioxamine at thesame dose.

Since these chelators can be easily and cheaply synthesisedand have no apparent toxicity at doses equal or greater than200mg/kg, it is expected that some would be of potentialclinical use in the treatment of transfusional iron overloadand other diseases of iron and other metal imbalance andtoxicity.

REFERENCES

1] Kontoghiorgh.es GJ. Scand. J. Haematol. 1986;37:63-70.2] Kontoghiorghes GJ. Molec. Pharmacology. 1986;30:670-673.3] Kontoghiorghes GJ. Inorg. Chira. Acta. 1987;135:145-150.

23

PHYSIOLOGIC INDICATIONS AND CONTRAINDICATIONS FDR EDTACHELATION IN ARTERIOSCLEROSIS OBLITERANS

R. LEV, R. MENASHE, J. BUSH, M. LEV

Cardiac and Vascular Medical-Surgical GroupEdison, New Jersey, U.S.A.

Fifty patients with clinical evidence of arterio-sclerosis obliterans were treated with magnesiim EDTAinfusions over short and prolonged periods of time.Biochemical studies of blood, hair and urine, andphysiologic non-invasive studies of the cardiovascularsystem were performed before, at intervals during, andfollowing a course of EDTA therapy. Specific trends inlaboratory and clinical improvement are noted in someparameters. There was no significant change in othersand some had regressive changes. The effects on kidneyand liver function were also noted.

From these physiologic data, specific indicationsand contraindications are suggested for EDTA chelationtherapy in individuals with arteriosclerosis obliterans )such as cerebrovascular, cardiac, and peripheral vas- jcular disease. 1,

i,I

24

CHELATION BRAZILIAN WAY SELECTION OF PATIENTSAND CLINICAL ASPECTS

T.MATTAR

The study concern to the results of the" ohe-lation therapy in group of diseases relatedwith atherosclerosis and senility. The clini-cal method was venous infusions of the ohelantagent (ethylen-diamino-tetraeetic-acid) (EDTA),in saline or glucose solution. We associate nu-tritional complements (vitamins), and compo-nents, to avoid irritation of the infused accor-dingly with the protocol of the AMERICAN ACADEMYOF MEDICAL PREVENTICS. We present a casuisticwith about 6.000 patients and more than 100,000treatments. The results are specified for eachgroup of localisation of the atherosclerosis{cardiac, cerebral, peripheric), and also withother pathologies indicated by the experienceof american plysicians. We conclude that chela-tion therapy is a therapeutical approach offirst line on the treatment of chronic degene-rative diseases, the first cause of morby mor-tality.

25

DECREASING THE RISK FROM Pu-239 AND Am-241 VIA CHELATION

C.W. MAYS, G.N. TAYLOR, R.D. LLOYD AND F.V. BiUIENGER

Radiobiology Division, Bldg. 351, University of Utah,

Salt Lake City, UT 84112, U.S.A.

Repeated therapy with Zn-DTPA decreased the reten-

tion of injected Pu-239 and Am-241 and also reduced the

risk from bone cancer in beagles and mice. The ;;one

sarcoma incidence in the mice given chelation therapy

generally fell below the dose-response curve for the

mice not given DTP A, indicating that the cancer risk was

reduced sore than that corresponding to the decreased

skeletal dose (Radiat. Res. 107, 296-306, 1986). Auto-

radiographs from beagles injected intravenously with

polymeric Pu-239 showed that daily Zn-DTPA therapy

preferentially decreased the deposition of Pu-239 in the

most carcinogenic locations of the skeleton, such as

bone surfaces near living cells. i

Supported by MCI Grant CA28314-7 and U.S. DOB r

Contract DE-AC02-76EV-00119. i

26

INACTIVATION OF COPPER OXIDASES BY CHELATING AGENTS.

L. MORPURGO, E. AGOSTINELLI. M.T. GRAZIAHI. L. AVIGLIANO*,AND B. MOWDOVI'

Centre of Molecular Biology of the C.N.R. and Department ofBiochemical Sciences, University "La Sapienza", Rome, Italy;•Department of Biotechnology and Biometry, University ofL'Aquila, T.'Aquila, Italy.

A comparative study is reported of the inactivating effectof N-N-diechyldithiocarbamate (DDC) on copper oxidases fromseveral sources, such as amine oxidase from bovine plasma(jJSAO), tsrcorbatc oxidase from green zucchini peelings (AO),and laccase- from the latex of the Japanese lacquer tree. BSAOInn? rwo similar tetragonal Cu(II) ions in a site that is opento Solvent access and to reaction with exogenous Uganda. AOend laccase are blue oxidases and contain several Cu(II) ionso- three different types. The single type 2 Cu is similar toBSAO coppers in the phisico-chemical and spectroscopic pro-perties find is the site of chelating =gents reaction.

In sir, a tenfold molar DDC excess very rapidly inactivates••(.• ..nd removes the type 2 Cu, without effect on the other Cuijns; e' :ept perhaps reduction of the type 3 coppers (1). Inthe same conditions DDC slowly and partially inhibits BSAO,binding about 50% Cu (2), and ia without effect on laccaae.In aceercbiosis and in the presence of reductanta it is ableto remove one Cu in BSAO (2), with almost complete inactiva-tion, and to remove in part the type 2 Cu of laccase (1).Two similar chelating agents, EDTA and nitrilotriaceta'te

(NTA) are also comparatively studied. NTA appears to be moreactive than EDTA in Cu removal. The study of NTA behaviourwith biological materials seems important in view of its widerecent use as an additive to detergents for washing machinesin Italy, end its suspect cancer agent's properties.

(1) Horpurgo L., Savini I., Mondovi' B., and Avigliano L., J.Inorg. fliochem. 1987, in press; (2) Horpurgo L., AgostinelliE., Befani.O., and Mondovi' B., submitted.

27

\V

PREPARATION AND CHARACTERISATION OF CHELATB LIGAHDSOP BIPHENYL AND DBRIVABIB COMPOUNDSR. MttLLBRUniversity College "Dr. Theodor Neubauer11

Brfurt/Mtihlhausen, Department of OrganicChemistry, GDRIn connection with our investigations on vegetableenzyme systems based on biphenyl derivatives thesynthesis and characterisation of 2,2f-dirhodanidebiphenyl and 2,2•-diamino-biphenyl and derivableoomplex compounds with transition-metal thiocyanateswas of interest. 2,2f-diisothiocyanate-biphenyl wasprepared by reaction of 2>2

l-diamino-biphenyl withthiophosgene (CSCLj,) in trichloromethane. Thereaction product precipitates under release ofhydrogen chloride as a yellow oil, which solidifiesto wax-soft oristals. 2,2'-diamino-biphenyl wassynthesized according to the method, described byBBCHAMP, by reduction of ethanolic solution of2,2t-dlnitro-biphenyl with iron and hydrogenchloride. The two ohelate Uganda obtained by thisprocedure were characterized by infrared, ultra-violett and^C-NMR spectroscqpic methods. Theposition of >?(CN), ^(CS), b (NCS) and 2 5 (NCS)bands In the infrared spectrum of 2,2'-dilsothio-oyanate-biphenyl prove a linkage between carbonatom and nitrogen of NCS group. The reaction oftransition-metal thlocyanate with 2f2*-diaminobi-phenyl respectively 2,2*-diisothiooyanate-biphenylin methanolia solution gave complex compound? ofthe type ML-(NCS) and ML3(NCS) (M: transition-metal | Lt chelate llgand). Significant bathoohro-mic shifts of characteristic v.'^ntione for example?(NH), (NH ) and >? (CN) refer ormation ofoomplexes (to oomplexatlon)• Thlse oc^plax com-pounds were characterized by in?7*ai•?,£. far infra-red, visible-solid state spectrtt anc --cadactivityand equilibrium InvestIgations, Biological testingresults of substances will ba t-.-ld.

28

DEVELOPMENT OF SOLUBLE SYNTHETIC POLYMERS AS A POTENTIAL DRUGDELIVERY SYSTEM FOR THE TREATMENT OF IRON OVERLOAD.

K.B.O'HARE, R. DUNCAN, P. KOPECEKOVA* and J. KOPECEK*Dept. Biological Sciences, University of Keele, Keele, Staffs.ST5 5BG England and * Institute of Macromolecular ChemistryCzechoslovak Academy of Sciences, Prague, Czechoslovakia.

Haemochromatosis is characterised by excessiveaccumulation of storage iron in many organs including liver,pancreas, heart and endocrine glands. Iron deposits areparticularly heavy in the liver and are associated withfibrosis, cirrhosis and hepatoma. Existing treatments involvesubcutaneous infusion of desferrioxamine (OF), which isexpensive and painful.

We have been developing soluble N-(2-hydroxypropyl)-methacrylamide (HPMA) copolymers as potential carriers forsite-specific drug delivery [1]. Efficient targeting of HPMAcopolymers to liver can be achieved by incorporation ofgalactosamine residues which promote interaction with the Ihepatocyte asialoglycoprotein receptor [2]. \

HPMA copolymers containing DF will be used for site- 'specific drug delivery to liver. Intracellular drug release ),can be achieved by lysosomal degradation of peptide sequences ibetween the drug and polymer, and the free chelating agent may ^subsequently bind iron in the secondary lysosome or, following \liberation in the cytoplasm. '

l^I-HPMA-DF-galactosamine conjugates have been prepared. )Following i.v. administration to rats, they are rapidly cleared [from the bloodstream and accumulate in the liver. The ability ,of•free and polymer-bound DF to mobilise iron will be compared |using an in vitro assay system to measure iron-DF complex jformation on incubation of chelating agent with ferritin or !59Fe CI3, Preliminary results in vitro suggest that conjugates jhave the ability to sequester iron. !

[1] Duncan R. et al. Makromol. Chem. Suppl. £, 3-12 (1985) :

[2] Duncan R. et al. Biochim. Biophys. Acta 880, 62-71 (1986)

29

NEW DEVELOPMENTS IN IRON CHELATION THERAPY

H.H. PETER

Pharmaceutical Research Laboratories, CIBA--GEIGY Ltd., CH-4OO2 Basel

Our worlc has been focussing on the evaluationof desferrithiocin, a novel microbial sidero-phor isolated from cultures of a streptomycesstrain. Its effectiveness in increasing ironexcretion was demonstrated both in normal andiron-loaded test animals. Oral administrationproved to be consistently more efficient thansystematic application. However, chronic toxi-city studies in non iron-overloaded rats anddogs revealed an unsatisfactory tolerabilityin the long term. Further research with thisclass of compounds will depend on the outcomeof the ongoing study on the mechanism of toxi-city. More recently, increasing effort hasbeen devoted to the evaluation of suitably mo-dified desferrioxamine-derivates. A particular,lipophilic derivative has already been iden-tified as a promising candidate for furtherinvestigations. Continuing experimentation withdesferrioxamine has meanwhile led to severalother potential applications for this chelator.

30

IS THIOL ANTIDOTES-INDUCED CHEMILUMINESCENCEASSOCIATED WITH PRODUCTION OF ACTIVATEDOXYGEN ?

S .R .Riba rov* . L.C.Benov**. O.H.Monovich**

*Dept. of Physics & Biophysics,MA,Sci. Med.-Biol.Institute, Sofia 1431, Bulgaria**Dept. of Biophysics, University School ofMedicine, Pleven 5800, Bulgaria

Four thiol antidotes (DMPS, DMSA, D-penicillamine,and mercaptodextran) were compared with respect totheir ability to induce luminol chemiluminescence(CL). It was found that only DMSA was able toinduce CL. The complete inhibition of the CL_by theenzyme superoxide dismutase suggested that 6Z wasinvolved. It was also found that DMSA initiatedperoxidation of phospholipid liposome membranes.In this case too SOD had inhibitory effect whichconfirmed the 0- production by DMSA. However,these results did not correlate with thiols aut-oxidation rate. On the other hand it was foundthat all thiols tested except DMSA were able toquench the CL induced by enzymatically generatedOp . It was confirmed in further experiments thattne quenching was due to 0~ scavenging by thethiols. This possibly explained the lack of cor-relation between thiol autoxidation rate andthe regisration of superoxide production.

31

THE RATIONALE FOR EDTA THERAPY IN ATHEROSCLEROTIC CARDIO-VASCULAR DISEASE

The International Chelatloa Research Foundation, USA andDepartment of Anatomy, Faculty of M«dloine, J.E.PurkyniUniversity, Brno, CSSR .

On the basis of numerous experimental ultrahistoehemical,analytical, enzymatic and functional studies of the bio-logical effeots of chelates(KDTA) and with several hun-dred items of literature data taken into consideration, anew conception of the EDTA mechanism clarifying its poly-therapeutic effeot has been elaborated and is presentedfor discussion*The results ef studies of the EDTA effect on calcium meta-bolism and calcium-dependant functions of the cardiovascu-lar apparatus are correlated with the effects of the cal-cium antaboniet verapamll*The question of using chelates in the treatment of athero-sclerosis in routine clinical practice is discussed*

32

Treatment of MeyHlmercury Poisoning by Subchronic Adminis-tration of sodium 2,3-Demercapto-l-Sulfonat (DMPS).S.G. Schafer

Institut of Pharmacology and Toxicology, D-8000 Munich 2,Nussbaumstr. 26, F.R.G.

Treatment of metal poisoning by chelating agents is introdu-ced since the discovery of British Anti Lewisite (BAL).DMPS a more modern drug is effective in arsenic or mercurypoisoning. Because of the long biological half life of mer-cury incoporated as methyhlmercury (MeHg), it was of inter-est^to study the long terra potency of DMPS in MeHg poisoningon Hg excretion and organ distribution.

was administered i.p. (1 mg/kg body wt.) to rats asHg-(MeHg-Cl). The animals were housed individually and

feces as well as urine was collected for 28 days. Simulta-neously whole body burden of Hg was measured daily by angamma spectrometer for small animals.In controls 48.2 + 10.9 % of the dose, in DMPS treated rats82.4 + 18.2 % were excreted within the experimental period.DMPS shortened the half life from 30.4 days in controls to12.5 days in the treated group. The DMPS treatment changedthe excretion pattern. Controls excreted 41.6 j 9.7 % of thedose with feces and 6.7 +_ 1.6 % only are measured in urine.After DMPS treatment urinary excretion of Hg was enhan-ced by a factor of more than five to 37.3 + 11.8 % of thedose, whereas fecal excretion of influenced only slightly(45.2 + 8.4 % of the3dose). DMPS treatment decreased tissueconcentration of Hg in all organs investigated upto80 and 70 % as compared to controls with exception of skin(incl. hair).

33

DIAGNOSTIC USE OF TECHIJETIUM-Q9m CHELATES

H. Spies

Central Institute of Nuclear Research, Rossen-dorf, GDR

The isotope Tc—99m is preeminent among medically

useful radionuclides due to its ideal nuclear

properties. In presence of reducing agents and

appropriate chelate ligands containing diverse donor

atoms (preferably 0, S, N, P ) , the most readily

available form of Tc-99m, the pertechnetate ion

TcO, may be reduced to give stable complexes in

lower oxidation states (III or V in most cases).

Modifications in the properties of the resulting

species lead directly to modifications in their

biological activity, and many of these complexes

have proved to be useful radiophar-maceuticals .

Complex formation of techaetium with selected che-

late systems and factors which govern the biodistri-

bution (such as size, charge, 1ipophilicity, stereo-

chemistry etc.) of medically important technetiura

complexes will be discussed.

34

COMBINATION THERAPY: A BETTER APPROCH TOCHELATION IN METAL INTOXICATION

S.K. Tandon

Industrial Toxicology Research Centre, Lucknovj -226 001, India.

Che la ting agents are used in the management of metal poisoningowing to their ability to remove toxic metals as their chelatesfrom the body. However, chelation therapy suffers from certaindraw-backs particularly when it is prolonged. Chelating agentsmight have toxic effects on the body tissues and disturb meta-bolic processes including essential element homeostasis. Theuse of vitamins in therapeutic doses has been suggested forurevention or treatment of metal poisoning. The combinationof thiamine and ascorbic acid has been more effective thaneither of them individually in prevention and treatment of leadintoxication. Simultaneous administration of various componentsof vitamin B complex particularly thiamine, folic acid or pyri-doxine enhances the therapeutic potential of calcium disodiumethylenediamine tetraacetate in lead toxicity. Ascorbic acidor ius combination with thiamine were more effective in enhanc-Ina the ability of oC-mercpto /3 -(2-furyi) acrylic acid (MFA)to reduce body burden of lead, restore lead sensitive variablesand enhance urinary lead excretion. It is likely that vitarrinsmay be facilitating the cell penetration by chelating agentstht-m-^ re(... ing their ionic character for a more effectiveciipmti-.n of mtracellular bound metal. The combined treatmentwith i.<libenclamide, a hypoglycemic aqent and calcium trisodium-diethylene triaminepentaacetate has proved advantageous asevidenced by greater eitmination of body cadmium and restora-tion of altered metabolism. Glibenclamide seems to potentiatethe biliary excretion of cadmium either by enhancing the gluta-thione synthesis or by forming lipophilic complex with cadmium.

Tne main advantages of combination therapy are i) lower dosesof fairly toxic chelating agents can be used, ii) if metal dissocia-tes from one chelating agent, it may be chelated by the othercomplimentry agent. The combination of polar and non-poiarcompounds may be useful in removing intracellular bound metals.

35

CAN IN VITRO METHODS RELIABLYPREDICT THE EFFICACY IN VIVOOF NEW CHELATORS?

David H. TAYLOR

Kernforschungszentrum Karlsruhe, Institute for Geneticsand Toxicology, Postfach 3640 D-7500 Karlsruhe and Universityof Heidelberg D-6900 Heidelberg, FRG

For ethical, legal or financial reasons scientists arenow required to devote serious attention to alternativesto animal studies for, at least, the early stages of screeningnew drugs, including potential chelating agents for humantherapy. Any in vitro test for a new chelating agent mustbe able to demonstrate the ability of the agent to liberatea specific metal from its principal binding sites in vivo.For example, a successful chelator for cadmium must be ableto mobilise the metal from its complex with metallothionein.Similarly, a chelator for plutonium must be able to mobi- ')lise that metal from its complexes with transferrin in .plasma, with ferritin or other proteins as well as, hope- »;fully, from its intracellular binding in lysosomes and fother structures in liver and bone. £

Several in vitro methods, release from transferrin, fer- \ritin or lysosomes have been used to screen a number of Jknown or potential chelators for plutonium and the results (have been compared with those from in vivo studies. It is jconcluded that in vitro methods can reduce the requirement !for animal experiments by excluding studies on those agents jwhich fail in vitro tests. However, positive results inin vitro tests are not reliable iridicator;; -.?f efficacy in jvivo. ;

36

CHELATE-INDUCED CHANGES IN METAL DISPOSITION: STUDIES ON 01-THIOCARBAMATES, PYRIDINETHIONES, XANTHATES AND DITHIOPHOS-PHATES IN RODENTS AND IN FISHES

H. TJALVE, S. JASIM, J. GOTTQFREY AND K. BORG

Dept of Pharmacology and Toxicology, the Swedish Universityof Agricultural Sciences, Box 573, S-751 23 Uppsala, Sweden

Ditniocarbamates, pyridinethiones, xanthates and dithio-phospnat.es are widely used in industry, agriculture and medi-cine. These substances are able to form lipophilic complexeswith metals. In the present study whole-body autoradiographysnd impulse counting have been used to examine the effects ofseveral compounds of this type on the disposition of 6 3Ni 2 +,I 0 ?Cd 2 + ssnd 2 8 3Hg 2 + in rodents and in fishes. In mice oraladministration of ethylenebisdithiocarbamate fungicides(zineb, maneb, propineb and nabam) together with 6 3Ni 2 + werewithout significant effects on the disposition of the metal,whereas dimathyldithiocarbamate fungicides (thiram, ferbam,ziram and sodium dimethyldithiocarbamate) induced markedlyincreased levels of S 3Ni 2 + in several tissues. Sodium pyridi-nethione and zinc pyridinethione, which are used as antise-borrheic agents in shampoos and as fungicides, induced mar-kedly increased levels of 6 3Ni 2 + and lff9Cd2+ in several tis-sues of mice and rats. Xanthates and dithiophosphates areused as mineral collectors in the flotation process. Xanthat-es were less efficient than diethyldithiocarbamate in in-creasing the tissue-levels of 6 3Ni 2 +, 1 0 9Cd 2 + and 2 0 SHg 2 + inbrown trouts, exposed via aquarial water.

A facilitated penetration through the cellular membranesof the lipophilic metal chelates is probably of great import-ance for the observed changes in the fates of the metals.The marked variations in the effects of the studied compoundson the disposition of the metals, which were observed insome instances, may be related to differences in the lipo-philicity and stability of the formed chelates.

Supported by the Swedish Council for Forestry and Agricul-tural Research and the Swedish Environmental Protection Board.

37

THE ANTIMYCOPLASMAL ACTIVITY OF 2,2'-BIPYRIDYLANALOGUES IN THE PRESENCE OF COPPER

H. VAN DER GOOT, H.-D GAISSER, M.A.H. DE ZWART ANDH.TIMMERMAN

Department of Pharmacochemistry, Vrije Universiteit, De Boelelaan1083,1081 HV Amsterdam, The Netherlands.

Previous investigations in our laboratory have revealed that for acompound to show a certain degree of antimycoplasmal activity, a2,2'-bipyridyl moiety, a largely planar structure and a certain extentof lipophilicity and a small amount of copper are required. Furtherinvestigations included the elucidation of die mechanism of action todesign structures of more active compounds. It appeared that thesecompounds form copper complexes and exert their activity viainhibition of enzymes of the energy yielding system. In tact thecopper ions are transported over the cell membrane by the2,2'-bipyridyl analogues and subsequently inhibit these enzymes. Inaccording to this result is the finding at MIC conditions using various !

ligands the same amount of copper has been taken up by the jMycoplasma cell. Furthermore some evidence was found mat stable jCu(I) complexes with lipophilic properties have high activity. [As it was anticipated therfore that neutral (lipophilic) and stable Cu(II) '-complexes might have antimycoplasmal activity some amides and Jamidines derived from l-amino-3-(2-pyridyl)isoquinoline were sprepared. By the synthesis of a limited number of compounds it was rrealized to decrease the MIC-value to 0.5 ng/ml in the presence of 10 'jig/ml CuSO4. The influence of various physieochemical parameterson the activity will be discussed. iThese investigations are supported by the Netherlands TechnologyFoundation.

38

Pseudothrombocytopenia, an EDTA-induced artifact.

A.Verbon, P.J. van der Schaar, P.J. van der Schaa

International 'Biomydical Center, Netherlands .

Pseudothrobocytopenia (PTCP) is an in-vitro phen-

omenon, that occurs in EDTA anticoagulated blood.

When an automated blood count is performed with

the widely used Coulter counter, in some people

an erroneously low platelet count is found. In

this situation platelets agglutinate in vitro un-

der influence of EDTA. The platelet agglutinates

are not counted as separate platelets in the Coul

ter counter. EDTA induces exposition of a crypt-

c ntigen on the platelet membrane. Platelets agglu

tinate due to an antigen-antibody reaction. This

incidence is 0.2-1%. PTCP is seen more often in

patients with a variety of chronic diseases.

To further evaluate the effect of EDTA on platel-

ets a standardized protocol is proposed, to diff-

erentiate between a true thrombocytopenia and a

combination of thrombocytopenia and PTCP;

39

CHELATQBS IN THE THEBAPY OF OCCUPATIONAL METAL INTOXICATIONIN CHINA

Vang ShiJon,Liu Jingyu, Shi Zhicheng,Occupational DiseasesCCenter,Third Hospital,Beijing

Medical University, Beijing, China

Two chelatars Na-DMS and Na-DMPS hare been used in thetherapy of occupational aetal intoxications in China since1963» wur olinioal experience showed that the excretingeffeots of Na-DMS for lead, aercury & oopper were definite.The excreting effects of Na-DMPS for mercury,copper,arsenio-were very successful, but not cadmium. The lead -excretingeffeot of Na-DMS was not inferior to that of CaNaiKDTAandthe aeroury excreting effect was similar to that of Na-DMPS.Na-DMPS also had lead-ezoreting effect,but ii was less thanthat of Na-DMS.The aost appropriate regimen of Na-DMS administration for

ohronio lead poisoning is 1 go per day intravenously for 3days. The most appropriate regimen of Na-DMPS administrationfor chronic mercury poisoning was 25Omg per day intramiiscu-lary.The excreting ability of Na-DMS and Na-BHPS were direct-lX« proportional to dosages in a certain extent, but large ''•doaages gave more side affects. The courses of treatment jdepended on the urine metal content and clinical condition. 1Generally, 3-6 courses were used in our most patients. The 'clinical symptoms in chronic l9ad poisoning could be much 'improved after treatment with Na-DMS. There had less effect \of Na-DMPS on relieving nervous and psychiatric symptomsin chronic mercury poisoning. Side effects would not beappeared when the dosage was well controlled. But allergioreactions could be seen in Individual cases.Quinamio acid as a new chelators was first discovered

in China. We demonstrated that it had beryllium-excretingeffect both on animal experiments and beryllium workers.

A COMPARISON OF THE EFFECTS FIVE CUPRURETICDRUGS ON THE TURNOVER OF COPPER IN HEPATO-LENTICULAR DEGENERATION

YANG REN-MIN ET Ax-.

Attached Hospital, Anliui College of Traditio-nal Chinese Medicine, Hefei, Anhui, China

BAL and D-penicillamine wore developed in thel9*+5 and 1964 specifically as the antidote forcopper and other heavy metals and have bean.used for treatment of Wilson's disease. Recen-tly, we describefsubsequently managed with DMSA,zinc sulfate and Herb water. The relative ef-fectiveness of these cupruretic drugs in trea-ting Wilson's disease from the urinary excre-tion of copper is D-penicillamine>PMSA>BALZnSO.> and Herb water in the magnitude of10:3.3:1.4:1.05:1, respectively. Nevertheless,recovery rate is lower in the Herb water ZnSO.and BAL groups and BAL, DMSA, D-penicillamine Lgroups have more side effects. Of them all, t,DMSA is the most potent and BAL appears to be rleast potent. On the whole, BAL has disavan- ptages and is far from the ideal drug. It's not juseful orally and increases the copper content jof brain when injected into muscular, a varia— 'ty of side effects occur. In addition, 5-10%of patients developed intolerance to D-penicil-lamine. DMSA, ZnSO. and Herb water may be pro-ved to be yet ones more fall back treatment forpatients who developed intolerance to D-penici-llamine.

BIPHOSPKOFATE PHABMACOLOGICAL PROPERTICSWHEN TREATING SOFT TISSUE CALCIFICATION

WELTISCHEV YU.E.,ALEKSEEVA N.V.,DIATLOVA H.M.

Moscow ,'rstitute of Pediatrics and ChildSurgery 'HITS try cf Health RSFSR

Dirhospnonate excretion from the organismtakes'placf- within the first 5-6 hours aftertaking the preparation. During the following6 hours iis*excretion smooth reduced andlessening its effect on calcium oxalate andphosphate crystals formation in urine is'•. oserved. That's why we think it is necessaryto administrate dipnosphonates twice a day.Machar.ism of diphosphonate effect is closelyconnected with their ability to stabilizephisphoiipide components of celular membranes.14C-aiphosphonates included into the membranephus^-holipids and provided a damage celularmembranes under pathological 39ft tissuescalcification. Diphosphonates inhibit the Jsoft tissue calcification both in experiments jand in man with pathology; they reduce Iinflammation of intersticial. Kidney tissue \bein^ under experimental and ectopical nephro- {calcionose; they also normalize alcaline \

Bhosphotaze and phospnolipase activity,iphosphonates prevent the ionized calciumincrease in serum under pathological calcifi-cation of soft tissue, thus lessening therisk of insoluble salt formation in tissueand pathological activity of immune andother reactions.

42

THE EFFECT OF EDTA, DTPA, VERAPA&IL ANT- •'.' \LCT•:O'-X/-: 09 I

METABOLISM OF Ca AND SOME OTHER BI'/AIlTUPb.CujNijCcFe,Mn,Mg) AND MONOVALENT(K,Na,?*( IONS

A.Zochmeistar.P.Matonoim.E.Hadag- w . . -iiSUBJsiP-- •>' r:

Department of Anatomy, Phenr.3.-; •'-•_tgyr d P i *Faculty of Medicine, J#E#Pur*.y-:<

In various s p e c i e s , both in viv .r, • * •:-i •< " rEDTA, DTPA, VERAPAMIL and CiLCI -Or " .-,:.••.;>.:-.;'ferent mechanism and with variou? ;r,-^n.-' . i" • . '.-pression to i n h i b i t i o n of the Ca i\?~\--\ .»;•».,••• " •"Ca ef lux) the i n t r a c s l i u l a r covi+ra< U1: CV"" r; ' u.a f f ec t the Ca-dep?jadent functions o l t-?** - . ' . -i ^paratus: They decr^&ss the rats ^ '> :iit. •-'\&:+^ u<?--.tt r a c t i l i t y , the in trs -ardiac ;J.I^ . riph^ r- '1 BI\ \ t • ,frequency, pro long the repo l a ; •*.:<.. '.351and ca l c i ton in alao c <sr«i3c t s* 1.. *" ^and the l i v e r an: S.;ic.r»aB« i t i r -n-.. Liiji^.; v Th» ' i'" ...in-tent in the bones i s screas^d by ^ietc a l c i t o n i n . A si<ooiflc--Tf*r dac&: oii'ying t.v

of chelatea and cn lc i ton in » .a f:rovf- ,-i*.pathic and at;aeroaclftrc-cic c e l c l f i c a t i :• -,and DTPA e* wel l as c a i c l t o i i n lidainii? at ion iv. .»••:*. 1-y-percalcemic in ncr«oca"ice»ic indiTidue.: avd hyp,.* ralain hyperealcemic onec* Calf iuria it» incr»»Be*S. i-vit»r r.»lfc*appl iaat ion and decreased af+«r r».lc. .^•^TI -ip-.J.;cft "-••'-.« 0raoncvalent ions the m$b8ten*ef> st>.-r •><» »>f?-'ct 'vJtt i n r A i i -l i s n j f E, Sa and P in the c rgrms, plasma i-n3 >»rlne« IK 1 •fcraet to c a l c i t o n i n and v«rspaail f ehs.l^ta'? «il?so B-5 gyxif A-oantly increase the e l i c - ia - t ioc of tur.-: . l\*a/y a s - i l ^ ap»p ? c i a l l y PbfCo,Fe,Mji and Si,, of *seejati&i W6'»r3.<s i t -.« ip.,

SDTA THERAPY OP INTERMITTENT CLAUDICATICN

A. ZECHMEISTSR. M, RUBIN

Medical Faculty, J.E. Purkyne Univ., Brno, Czech.Georgetown Univ. School Medicine, Wash. D.C., USA

The intermittent claudication of peripheralvascular disease arises from a tissue deficitof oxygen and nutrients during exercise. Anecdotalclinical reports have suggested the therapeuticbenefit of EDTA therapy. Controlled clinicalinvestigations are now in progress to provide adefinitive answer to the question.

Presently available therapies have been developedand applied to individual components of the complexetiology and pathology of the condition. Incontrast the utilization of EDTA chelation affectsa broad basic spectrum of involved processes. Inaddition to it* wall studied hypocalcemia withphosphaturia and calcinuria coincident with itsurinary excretion, intravenous EDTA causes animmediate PTH response within the physiologicplasma calcium range. Other noted hormonal,cellular md metabolic effects can arise from thecalciuui cnannal blocKing capability and membraneInteraction;" of the compound. Interaction withiron, aiac and other trace elements modifiestheir biologic role in free radical, iipid andcarbohydrate reactions. In addition EDTA has thecapability of enhancing peripheral blood flow byvasodnatation and the encouragement of thedevelopment of collateral circulation.

44

P O S T E R S

45

EFFECTS OF DISULFIRAM AND ITS METABOLITES ON CADMIUM

TOXICOKINETICS.

Ole AndersenDepartment of Environmental Medicine, Odense University,3.B. Winsfcws Vej 19, DK-5000 Odense C, Denmark.

Disulfiram (antabuse ) is used for avoidance therapy of alcoholismand chelation therapy of nickel allergy. The active metabolite,diethyldithiocarbamate (DDC) forms lipophilic complexes withvarious divalent metal ions, including Cd++.The present work investigated effects of disulfiram and DDC onintestinal cadmium absorption and organ distribution of cadmiumusing single low dose exposure to 10'Cd and chelator or cnronicexposure to both cadmium and chelators. Oral administration ofantabuse and intraperitoneal administration of DDC increasedintestinal cadmium absorption very much, while oral administrationof DDC increased the absorption less, but still highly significantly.The organ distribution of cadmium was significantly changed byadministration of disulfiram or DDC: The cerebral deposition wasincreased, while the hepatic deposition was reduced. The resultsindicate the possibility of increased risk associated with dietarycadmium exposure in persons treated with disulfiram.

47

HAViOH OF HEAVY METALS IN PLASMA, ERYTHROCYTES AND URINE•ILJWINU INTRAVENOUS INFUSION OF CaEDTA IN METAL WORKERS

Deparrmen; of I'ublie Health and Hygiene, Medical College ofOita, O±ca 3Vi-56, JAPAN.

To evaluate »"hs effects of calcium disodium ethylenediaminetetraacetate (JaEDTA) en the behavior of eight toxic oressential metals in plasma, erythrocytes and urine, weadministered CaEDTA in 1-hr intravenous infusion to eighteenr^tal founders exposed to lead (Pb), zinc (Zn), copper (Cu)and tin (Sn). Their blood Pb concentrations ranged from 16to 5'-' '.mean 34) yg/dl. The plasma and urinary levels of Pbwere highest 1.5 hrs after the infusion was started, whereastne erythrocyte and whole blood concentrations were lowest.Similarly, 1.5 hrs after start of CaEDTA infusion, the plasmaand urinary levels of Sn and manganese (Mn) were highest; theerythrocyte concentration of chromium (Cr) was lowest(urinar> excretion of Cr was highest within 1 hr followingstart of CaEDTA infusion). On the other hand, the plasmaconcentration of Zn fell rapidly following CaEDTA infusionand became lowest 5 hrs after start of the infusion; itserythrocyte concentration reached the highest level duringi.hs period 5 - 1 2 hrs following CaEDTA infusion (urinaryexcretion of Zn was highest during the period 1 - 2 hrs afterstart of CaEDTA infusion). Urinary excretion of Cu andcadmium (Cd) was highest during the period 2 - 4 hrs afterstart of CaEDTA infusion, whereas urinary excretion ofinorganic (and total) mercury (Hg), delta-aminolevulinic acid(ALA) and coproporphyrin(CP) was highest within 2 hrsfqllowing the infusion (urinary volume was significantly highwithin 12 hrs following CaEDTA infusion). No significantalteration was found in the plasma and erythrocyteconcentrations of Cu, Cd and Hg. The remarkabie differencein the kinetics of these heavy metals following, CaEDTAinjection is discussed in the light of these findings.

48

RADON DECAY PRODUCTS: DMPA DECREASES TISSUE POLONIUM-210

M.M. APOSHIAN, H.V. APOSHIAN, J.L. DOMINGO, J.M. LLOBET,ZHENG WEI and R.C. DART.

Department of Molecular & Cellular Biology, university ofArizona. Tucson, AZ, USA.

Radon-222 and its decay products are natural-occurringenvironmental health hazards of increasing importance.Polonium-210, an alpha emitter, is one of the mostdangerous decay products. It is believed to combine JJT.vivo with thiols and thiol-containing proteins, as doheavy metals. The activity of DMSA, DMPS and DMPA,water-soluble dimercapto metal-binding agents, inprotecting rats against the lethal effects of 210-Poand in decreasing the tissue content of 210-Po havebeen investigated. Rats given 210-Po (36 vC/kg) ip hada median survival time (MST) of 39 days. The MST wasincreased to 106 days by sc administration of anyone ofthe three dimercaptans. After 21 days, kidney andspleen levels of 210-Po of rats given 210-Po (0.4uC/kg) sc, followed by DMPA beginning one hour later,were approximately one fourth of those of the untreatedcontrols, and were significantly lower than those thatreceived DMSA, DMPS or N- acetyl-L-cysteine (NAC).Trien was ineffective. NAC consistently increased the210-Po content of all tissues examined. The kidneys ofanimals given 210-Po, followed one hour later with acourse of DMSA, showed a much slower rate of excretionof the DMSA-Po complex then the DMPA-Po complex.(Supported by OHO2185).

A\.•".. -JNJSTS FOR ACUTE ORAL CADMIUM CHLORIDE INTOXICATION

M. ;-.. v SINGER, M. M. JONES, M. A. HOLSCHER AND W. K. VAUGHN

Dep-ircz:::v.i. u£ i. "?.r:istry and Center in Molecular Toxicology,Vanderbilt Univ,-. • ity, Nashville, Tennessee, 37235, U.S.A.

An exasiudi.'on has been carried out on the relativeefficacy of a numb- i of chelating agents when acting as anta-gonists for oral ca.iroium chloride intoxication in mice. Thecompounds were administered orally after the oral administra-tion of 1 mmol/kg of cadmium chloride. Of the compoundsexamined, several were useful in terms of enhancing survival,but dy far the most effective in both enhancing survival andleaving minLmal residual levels of cadmium in the liver and!.na kidney, was rueso 2,3-dimercaptosuccinic acid (DMSA).Several polyaminocarboxylic acids also enhanced survival. Themost effective of tnese in reducing liver and kidney levels ofcadmium were diethylenetriaminepentacetic acid (DTPA), trans-i,2-.-UHmir^t.vclohexane-N,N,N'N'-tetraacetic acid (CDTA) andtriethylene-d-raminehexaacetic acid (TTHA). D-Penicillamine()V\) was found to promote survival but also led to kidney k

cadmium levels higher than those found in the controls. jSodium 2,3-diraercaptopropane-l-sulfonate (DMPS) was as effec- [tive in promoting survival as DMSA but left levels of cadmium 'rin the kidney and liver which were approximately four times tgreater than those found with DMSA.

50

THE EFFECT OF BIS( HYDROXYETHYL)DITHIOC^BAMATE r,\!

THE EXCRETION OF 63Ni IN RATS

D. BITTNEROVA. K. BLAHA 3rf . M. CIKRT,. BABICKfa,. ^

Institute of Hygiene and Epidemiology4

•institute of Physiology, Pr-i-gue,

Previously it was reports.-1- t i c;i ;:-',vld ;.•; J.~

cerbamate affects both organ -"i t r ib-.t • •>,; : excre

tion of Ni while eosnei ct^ar a p".,s log *-•?•» e ;ef fee

tive. In a continuation of ctutiy .:!.*alii'-; *vit.i effe-

cts of biefhydroxyethylJdithioci-rDem^tc FPT'" on

Cd excretion in rats we uwe ter?r»d the f."1'.,-. •»,-;•••£

of DEDTC on the Ni excretion. T:?; bal* a.>cte of 2

groups of rat« «.¥?sr# cennulatad an6 $'-t.ttr 2 r .-'iaal

were injected with 63NiCl2 (655 ucs Ni/W, ^3 ':

(500 sg/kg) was adainistered luodiately »*«' s

•ttal injection, the eacond group vs«a injerta^ *sx±h

saline. In the control group the cusul&tive iliary

excra'icn was 144.2*70 3 ng Ni per 6 h (0 tv-t.O::'

of the adninistered dcoe) and 5£,4*11.? ug N.1 p^r

18 h (34.2^5.0 %) w»e sxcreted via urine. D.o r id-

Ministration significently dooreaeed both £u- liH#

ry (40.3^17.0 ng Ni per 6 h) and thr urinary ?-«c.re~

tlon (1.02^0.32 ug Ni par 18 Si). Further experiwanr

are focused on the effect of DEDTC on the orris, iis

tributicn of °"Hi,51

THE EFFECT OF SIMULTANEOUS ADMINISTRATION OF TWO

DITHIOCARBAMATES ON Cd EXCRETION IN RATS

K. BL.AHA Jr., M. CIKRT. L. KASPAROVA. M.M. JONES8

Institute of Hygiene and Epidemiology, Prague, CSSR.sVanderbilt University, Nashville, Tenn., USA.

we have reported that bis(hydroxyethyl-

dlthiccsrbaatate (OE) significantly increases the bi-

liary excretion while 4-carboxamido piperidinedi-

thiocsrbaaate (INA) affects only the urinary excre-

tion of Cd in chronically exposed rats. DE increases

the concentration of Cd in the brain. In attempt to

enhance th$ total excretion and to prevent redistri-

bution of Cd into the brain the simultaneous i.p. ad- '

ainietration of both chelators in rats exposed to Cd <:

In drinking water (50 mg/1; 39 days) was tested. The {

rats were divided into 4 groups : A-control, B-INA, ]

C D E , D-CE>INA. in all cases 2.46 m«ol/kg of chela- ;

r

tore m&& injected. It was found that both biliary i

&n6 urinary excretion of Cd in group 0 was signifi-

csntly higher coaparing with groups B, C. Using the

combination DE+INA in rats exposed for 180 days the

higher total excretion of Cd has been confirmed. Mo-

reover, significant decrease of Cd concentration in

brain and kidneys was observed,

52

CALCIUM EDTA TOXICITY IN THE HAItULaBAS^TiUCTUHALEFFECTS ON SKIN COLLAGEN

V. B. BRAIDE* V. GRILL Sr C, PBLBJBLIG

•Department of Pharmacology, University of Calabar,Calabar, Nigeria? and Inscitute of Hume.-; jknatc ay,University of Trieste» Trieste; liajy

The effect of Calcium tiehylenso ^..rie';^ t;..'••> rtar,(CaEDTA) infusion iv en skin \; •. r.T&strv;\t- -r wasstudied in the rat, with t:.~ a:. : cf L;wa;;,:'i:r:electron microscopy* High my unification •O-nctrcnmicrographs of oollaaer; fibril? •#• i\ ax--..;.:,= ed. '-itha computer aided image analyFi;rf \.i\ ree>.^c\ -ffibril diameter and "D-spac-:,*;•', C!a«Dr:A cy-AS-:--marked depletion of coll?gen. fibi \ir .!.{• tbc sVin.The collagen fibrils fro^: OeSuTA tr • •:• csd rat^exhibited significant inerepres iv; "I;-Bpao:^-"(about 30'A-) and diameter (abou'o 4O>>) co3>pai*j-i "•saline treated controls. The ficr-.-.blaytsi in V:iuof CaSBTA treated rats appeared to cont? ;.n a-Tcprocoila^en fibrils than tVio a of control skin.These findings are consistent -j'h B^rli^: ••\r-chemical data indicat;r,c ti::ib CaijjTA enha>. <*£noj i.agen degradation in the rat. 7b J.S .. 1P?O..oasible that CaSDTA ft ratment TVXV causs ii;h bitiouoT coJlagen secretior by fibroblat-ts into '.heextracellular matrix» in v K w of rep-its that t''ipchelate inhibits pos-fc-translationsi ensytne^ :;;/chela ting endogenous trace rvietals required loroptimal activity* irsportant for +-he -vecacollae-en b',r cihe fib.'oblasts,,

THE EFFECT OF CADMIUM AND CHELA TING AGENTS ONCuZn SUPEKOXIDL DISMUTASE ACTIVITY IN LIVER OFMICE

D.Caisova, V.Eybl

Department of Pharmacology, Medical Faculty ofChaz'les f.niversity, Plzen, Czechoslovakia

CL,iii;;es in activity of CuZn superoxide disusu-•;••!?•; (CIZUSOD) were determined in ethanol-chlo-rufoxm trra ted liver homogenetes of ICR male mi-ce (acout '°3s)« Mice were injected either withCd ( JO y';,"u]/kg s.c. . decapitation 17h aftertreatment) or with, chela ting agents (CA): CaBTPA ,7,iuJTPA.•, DMPS, DMSA, desferrioxamdLne (0,6 iruuoj/kej.p., decapitation 2h and 19h after treatment).CA vex1* aj*<> ^pti^led simultaneously vitL Cd (de-

+.'tion I 93"" aftfr treatment) or after 17h-in-net; of Cc\ (decapitation 2h after tl\e »eco:<dtmeat). por determination of CuZaSOD the

of inhibition of reduotioxi of nitioblue

Lv 0~ generated via photoreductionY riboJ .'3 vi'i was u&ed. CA when injected alone'• >i'S?-' i-1 ••-. cii Lioally significant increasing of-u'.w' ') aofcivity in groups decapitated 2h after.eatmon;. Or- the other hand Cd caused inhibi-ts c oi er yn... activity. Combination of Od andCA H4.. reaped ihe activity to the level of con-f -Hi.

THE EFFECT OF DESFERRIOXAMINE ON DISTRIBUTION

AND EXCRETION OF Al IN RATS DRINKING WATER

CONTAINING Al-CITRATL

M. CIKRT, P. LEP§f, K. BlAHA, Dr..

L. KASPAROVA". AND D. BITTNEROVA

Institute of Hygiene and Epidemiology, Prague,

CSSR

Female Wistar rats were loaded with Al-cit-

rate in drinking water (1.33 g.l" ) for 92

days. Rat's bile ducts were cannulated, bile

and urine were collected. The effect of i_p.

administration of desferrioxamine (DSF) on

the distribution of Al and excretion of Al

and Fe was tested. Al and Fe were determined ':

using AAS aethod. There were not significant {

differences in the distribution and excretion j

of aluminium between untreated and DSF-trea- ,

ted rats. DSF significantly increased bili-

ary as well as urinary excretion of iron. .

OF THE ANTIDOTAL EFFICACY OF CHELATING AGENTS UPON

Al-jTc rOXICITY OF STRONTIUM IN MICE

j.L.DOMINGO1,A.ORTEGA1 ,J.M.LLOBET 1^.L.PATERNAIN 1 and

J.C0R8r.LLA:

Laboratory A Toxicology and Biochemistry, and Ttepart/nent of Toxicoloyy,raculty of tediane, University of Barcelona, Spain

TTKS relative efficacy of 15 chelating agents in alleviating acute

slrontiun nitrate (ip) mtoxication has been determined.For a level of 6.52

imoi/kg ip of Sr(N0~)o (LDoj). the ip administration of chelating agents at

0.5:1 ri'KJ 1:1 role ratios resulted in a significant enhancement of the sur-

vival rate only for malic, oxalic.ascorbic.glutamic and tartaric acids,Tiron,

C-iEDTA ,'xj CaDTPA.

Try.-' •terapeutic effectiveness of these ccmpounds was assesed quanti-

tatively by fH-v;d:no the L D ^ of treated mice by the LCU control.The first

groups received the chelating agents (1/4 their respective LD^Q values) five j

ninutes after the lp administration of different dosages of strontium nitrate [

(677-2325 mg/kg).The control group received 0.9% saline instead of the chela- ,

..;« ayent.CflDTPA (1.7b), CaEDTA (1.70) and malic acid (1.62) showed the I

best results.Glutamic acid (1.52) and Tiron (1.47) showed also a good the- i

rapeutic effectiveness.Oxalic acid (0.87) should not be used due to its high f

toxicity.

56

DESFERRIOXAMDJE AMD CaDTPA IN INDIUM INTOXICATION

V.EYBL, J.AASETif, M.KOUTENSKA, J.KOUTENSKf,J.SfKORA

Department of Pharmacology, Faculty of Medicine,Charles University, Pilsen, C*SSR;*Hedmark CentralHospital, Elverum, Norway

The experiments were performed in male mice(ICR, SPF, 2k-Z6« b.w.). The effect of CaDTPA inddesferrioxamlne (DF) on the acute toxicity ofInCl~ was compared, Chelators injected sc imme-diately after the ip application of InCl at achelator : In molar ratio 10:1 decreased-*slgnif i-oantly the toxicity of In. At the molar ratio 5:1DF was more effective than CaDTPA. No effectcould be shown when the chela tors (10: l) were in-jected at 90 min of the experiment. In the nextexperiment the effect of chelators (injected im-mediately at a.molar ratio 10:1 after the ivapplication of InCl3-Ot5i«g JaT /kg) on thewhole bodar retention and tissue distribution of \In at 24 Ti of the experiment was studied. The '•effect of both chelators Injected at 2k Ti of the [experiment (100:1) was also examined. CaDTPAmore effective than DF. In another experimentInCl and In labelled DF and DTPA were admi-nistared iv. The lowest In retention was foundafter the application of InDTPA.

-UTEP SIMULATION OF THE ABILITY OF 2-MERCAPTO-3-PHENYL-Xr-ENOIC ACID TO MOBILIZE THE L.M.W. FRACTION OF ZINC(II)BLOOD PLASMA.

y<._: JJiELI-A* N. GARRIGA*, A. IZQUIERDO* and D.R. WILLIAMS1

* Depai- an. r.* cie Qulmica Analltica, Universitat de Barcelona,Diagonal •"•.'/, 08028 Barcelona, Spain.

t Dcpartme.it _-: Applied Chemistry, UWIST, PO Box 13,Cardiff CrJ ?XF. UK.

The biolocjical activity of 2-mercapto-3-phenylpropenoicacid seems to DC: related to its metal complexing ability,particularly with zinc. This agent has shown to influencethe distribution and metabolism of zinc in vivo (1 - 3 ) .

Thr effpjtonthe low molecular weight zinc ion distribut;on in blood plasma caused by the administration of 2-mer_capto-3-phenylprcpenoic acid has been evaluated by meansof computer simulation using the ECCLES program (4). Theprogram calculates a Plasma Mobilizing Index (PMI) for themetal icr; and for a range of drug concentrations. The for-mation constants required for the simulation were previous ^]y determined by potentiometric titrations (5). i

In common with many sulphur-containing agents, 2-mercapto- 13-phenylpropenoic acid brings about significant PMI values '-for zinc, thus corroborating the results obtained in in vivo 'studies. !)

(1) N.J. Prakash, P.J. Schechter, E. Giroux and A. Sjoerds^ |ma, Clin. Exp. Pharmacol. Physiol., 1977, 4, 17. |

(2) E. Giroux, P.J. Lachmann, B.G. Petering, N.J. Prakashand P.J. Schechter, Biol. Trace Elem. Res., 1983, 5, 115.

(3) E. Giroux and P.J. Lachnann, Toxicon, 1981, 19, 481.(4) P.M. May, P.W. Linder and D.R. Williams, J. Chem. S o c , |

Dalton Trans., 1977, 588. !(5) M. Filella, N. GarrigaandA. Izquierdo, J. Chim. Phys.,

1987, in press.

58

TOXICITY OF DTPA ADMINISTERED INTRAVENOUSLY OR ORALLYIN RATS AND BEAGLES

S. FUKUDANational Institute of Radiological SciencesjChiba 260JAPAN

DTPA is an expectable chelate p.gent for tr.e redtici-i.' ofthe risk of radionuclides induced cancer and th-« , re'-^.tion ofshortening life span, because it is gersrally ai;> t- •• *" i- candecorporate radionuclides effectively frian '-he hur •; - ••*.;-•.However, there have been few reportr "hat i r ii i r..v« arv-g i; :human use.

When Ca-DTPA of 30 or 300 vs"l/i-j d-' <-. • w«a c. .Uy uhnir-istered to rats for 6 months or to neagl-i fnr i vout*., *•[-<-.mild damages for liver, kidney were- biachpnioally obser- '•, Thacongestion and hemorrhage in the iutestin. was also «nat -m.ral-ly or histologically observed, in which VPS '.robnh* o-'-isc'by the vascular penr.ie>ility acticr if D7?\ 0:; i.b*» ?th*' hc»nc;, '')almost no changes were se<.r by Zn-DTPA. •

When Ca-DTPA was intravenously ir.iocce^. t- .a.t'i ix \beagles, almost no changes were observed. Povever, tht ypo- icalcemia was induced by Zn-DTPA of more t^an 30 v mcl/kg -JMSt.9, 1the heart failure was observed with inc..-sas'.*>ig of doses. \

The results show that the different effects are obso-ved Jby the chtanical forms or administration routes ~>£ DTFA «*/n Jthat there are almost no diffevinces on its tcxicity be.? :eerrats and beagles.

In conclusion, it might be .state that Gt-DTFA shouJ i he-injected intravenously for fhe intensive care for radiationwokers, and Zn-DTPA should be administered orally for a ito-longed treatment. Also, since the almost r»o species defer-ences on DTPA effects between rats and beadle*, the dataobtained from anl-nats may be available fo< estimating rb«?toxicity of DTPA for human use.

DYNAMICS OF WHOLE BODY RETENTION OF REPEATEDINTERNAL CONT.AMINATION WITH 95Nb AND I44ce RADIO-ISOTOPES IN MICE

A. Gachalyi, J. Namenyi, I, Szegedi and P.L. Varga

National Research Institute for Radiobiology andRadiohygiene, Budapest, Hungary

The probability of occurence of multipleinternal contamination is relatively high in somework places exposed to radiation. However,experimental date regarding repeated contaminationwith radioisotopes and the efficiency of combinedtreatment are rather incomplete.

In fission products formed in nuclearreactions, 95Nb and 144Ce are present in 4,9-6.2%.Therefore, animal experiments were undertaken inorder to determine how the deposition and elimi-nation of these radionuclides can be alteredbeneficially with the administration of complexforming compounds in single or combined treatmentforms,

fron our results it can be stated that the ilo^g-lifo comoonsnts belonging to the various /retention curves indicated an increase in the £deposition of beta radioisotopes after repeated 'fintake consequently the speed of elimination ?decreased. }

60

POSSIBILITY OF REHAL DYSFDNCTIOK AS A Kfr;SvJi<T OFEXPOSURE TO CADMIUM

MARE* JAKUBOVSKI, JANUSZ XBDULSKX

I n s t i t u t e of Occupat ional S4««-ici.,*fe U><k6.,

The c r i t i c a l ccncejc•• rakidney, the d a l l y Intakedata suggest that the 3SJ%J».vI -W of '^rss^ ;,u t-".«s-l a t i o n I s not at r i sk iroia <-n.'.~rz.xv:z AX-.^S.. r-eHowever, s n a i l groups o** p»a»rsi f-r»;-.v-aiA ;\< ~t*. -..•>• u bt»at r i sk created by llvJLae t o* - l o ^ ' *J-- " •.•2-;«eproximity of c^Jinlum owi.ttlp-*? w n r ; .--,

This papor vaa minted *»r ' •nxl^^.i ... a, - .i»b a s i s of ava i lab le liters.tv?i-*>own i n v e s t i g a t i o i i i , of tli» xi^v of rc t l o n tfflon^ arwlx populat x '-r»r i.,ih*.btx i jeformerly a c i prsnaotly 2c>tit»ii«iiii*fce'i «j;j;aThe obt ale. *d hi tli -ar i.» r * su l v -£ of" i'iv* a t icarried out i n t>I-i--rly poopl * i•s.vl*;^ Tor s*, 1 v,t l a e on stsch t»ri ' torl*fe ^u^g-fst "aai i.u »j:' £ *••of s l i g h t incrsRse of ca.dtciu:.'. l a v e l s it= bloo--*.urine as ccmj^ai'o4 to oo-itrol grroupn ao defl^o ?:trends toaarda tb« JcJ-tlney dy-*f wi*tetl on i n tbe /of incr««fei«ett excret ion of lov »aoleouJ«y. prstft/..or amlntoacids In u^^n* liave bee

61

Ik

\

THE EFFECT OF ZINC ON THE DITHIOCARBAMATE-INDUCED MOBILIZATIONOF AGED CADMIUM DEPOSITS IN MICE

S. G. JONES, M. M. JONES, M. A. HOLSCHER AND W. K. VAUGHN

Department of Chemistry and Center in Molecular Toxicology,Vanderbilt Univ., Nashville, Tennessee. 37235, U.S.A.

In comparison with similar experiments in which no rincacc-t^te was used, the addition of small amounts of zincacetate to sodium N-methyl-N-dithiocarboxyglucamine producesa significant increase in the amount of cadmium mobilizedfrom the liver =md kidneys of mice loaded ip with 10 mgCdCl2*2,5H2O/kg two weeks prior to the initiation of treat-ment. Neither treatment results in the transport of signifi-cant amounts of cadmium to the brain. The injertion of zincacetate alone did not produce this effect. Experiments inwhich zinc acetate in drinking water was administered tocadmium-loaded animals showed that the liver and kidneycadmium le\rels were significantly increased, presumably viazinc ned'-ated >rocesses in which cadmium from other organswas mob-iized to the liver and kidneys.

62

PROTECTIVE EFFECT OF DIETHYLDITHIOCARBAMATE ORMETALLOTHIONEINS ON CADMIUM-INDUCED LUNG DAMAGEIN RATS

V. KOBRLE, M. CIKRT, J. HAVRDOVA, E.EFFENBERGEfcC'VA',

E. MlfiE JOVSKA', K. BLA*HA Jr., J. HURYCH, M.M. JONES

Institute of Hygiene and Epidemiology, Prague,CSSR,Department of Chemistry, Vanderbilt University,Nashville, Tennessee, USA.

On the model of lung tissue damage after intra-tracheal instillation of cadmium chloride theeffects of metallothionein (MT) synthesis inductionor diethyldithiocarbamate (DDC) treatment werestudied. The synthesis of MT was induced by a sin-gle i.p. dose or chronical oral treatment of CdClp.

The typical changes of Cd-induced lung damage(increased lung weight, and collagen content;decreased lung elastin; increased number of freecells and elastolytic activity in broncho3lveolarlavage) were significantly different after Cdinduction of MT and DDC treatment. Administrationof ZnClp did not influenced substantially thestudied parameters.

63

1SSP0NSS OF RAT LUNG TISSUE FOLLOWING CADMIUM

Y« JCOfidLE, o . HURYeri, J - SLABf, P . FRIC~,

r. r:rrwKi;Er.-"-sRcvi[t R. H O L U S A , E . MIREJOVSKA*

Institute of Hygiene and Epidemiology, P r a g u e , ,Laboratory of Gastroenterology, Dept. of Medicine,School of Medicine, Charles University, Prague,CSSR.

k single intratracheal instillation of cadmium(10 pg Cd /lung) induced an initial inflammationfollowed by metabolic changes in connective tissueproteins. It is a biphasic process where the earlyphase reflects destructive lession, the further onereparative changes of lung tissue.

The early phase was accompanied by increasingweight of lungs, elevated number of free cells inbronchoalveolar lavage as well as increased elasto-lytic activity of alveolar maerophages. In broncho-alveolar lavage also an increased amount of subs-tances containing bound hydroxyproline was detected.They were classified as degradation products ofa glycoprotein (alveolyn) formed simultaneouslywith components of lung surfactant by pneumonocytestype II. Increased elastolytic activity eliciteda partial destruction of lung elastin.

The further phase was characterized by repara-tion of the damage tissue in part by formationof collagen scars. Both collagen and elastinsynthesis were stimulated. A permanent fibrotiza-tion of lung tissue and formation of emphysemawas the result of these changes.

COMPARISON OF MgEDTA AM) NapEDTA ~ ACUTE TOXI-CITY AMD EXCRETION VIA THE URINE

J.KOUTENSKY, M.KOUTET-rSKi, V.EYBL

Dept. of Pharmacology, Faculty of Medicine,Charles University, Karlovarska ^8, 301 66PiIsen, Czechoslovakia

The acute toxicity of MgEDTA and !NaQEDTA wascompared in experiments in mice, T ie excretionof this chelates via the urine was studied inthe experiments in rats by paper chromafcogra-phy. Various chelates of EDTA with Mg, C-a andothers elements were detected.

MULTIVARIATE ANALYSIS OF EFFECTS OF SELECTEOCHELATIN6 AGENTS AND RELEVANT STRUCTURE-ACTIVITY>-LATIONSHIPS

u* LMASS

Sezirkskra ;k«nhaus "Friedrlch Wolf",•Carl-Marx-Stadt, German Democratic Republic

Multlvariete statistical analyses were per-formed with tho intention to classify

(i) chelating agents with respect to theirinfluence on the distribution in the humanor animal body and on the elimination ofdifferent metals and metalloids,

(ii) the tissues according to the distributionpattern of metals under chelation,

(ill) metals and metalloids owing to thosechelating agents preferably interactingwith them.

By factor analysis, for example, it could beshown that three significant factors satisfac-torlly represents the distribution patterns ofmercury and other metals under the influence ofdifferent chelating agents.

As possible reasons of the different chela-ting properties (i. e. the (conditional) stebil-ity consult etc.), the variation of physicoche-mical properties of chelating agents and of theelectronic structure of metals will be conside-red. In relevant cases, regression or discrimi-nant analyses were performed to illustratestructure-activity relationships.

Conclusions with respect to the treatment ofmetal poisonings will be discussed.

66

THE OXIDATION OP NADH BY VAHABATB PLUS SUCARS

S. LIOCHBV, I. gRIDOVICH*Institute of Physiology, Bulgarian Academy ofSciences, Sofia, Bulgaria; Department ut Bio-chemistry, Duke University Medical Center,U.S.A.

Sugars and sugar phosphate enables, vjm^d&^e tocatalyze the oxidation of BA1>H. Sur>ero'*i " *?:lswu~ta»e inhibited this oxidation, Xncuba••f •,?. of ma-gars with vanadate, prior tc edJ^.^I^a o" KAr:J, ac-celerated this oxidation of *ucsequontj.^-aca;dBADH and eliminated the leg phase oiijsi-vireSugars are knon-ii to form coffiple-x.es with ve2uand then to reduce it. Incubation of sugar*-'ranadate also remilted in the appetirfcuxoblue-green color probably associated with &vanadyl-vansdate complex. It appears thatreduce vanadate to vanadyl which t in iurnf wducei:0 2 to auperoxide (0^) and that vanad^ie ^IUH 0«then catalyzes the oxidation of HAI)(P) i by a ?i?>*radical chain reaction. Such oxidation of MiVB'3P)Hmay account for several of the biological effectsof van&date.

6't

THE PROTECTIVE /CTIGN OF OELATING AGENTS IN EXPERIMENTAL ZINC POISONING

J.M.LLCBET1,A.BOSQUE1,M.T.COL0MINA1,J.L.OCMINQ01 and J.CORBELLA2

Laboratory of Toxicology and Biochemistry, and TDepartjrent of Toxicology,

faculty of Medicine, University of Barcelona, Spain

Sixteen cheiating agents were administered to mice by ip injec-

ticn 2u vsvu al dosages in crtfer to ccnpare their relative effectiveness in

prevention of cfeath after a single parenteral injection of zinc acetate.For

?. sevel of 0.4S- rnnol/ko of ZnAc~ ( U W and the cheiating agents administered

at 2:1 and 5:1 role rat io, CaEDTA,CaDTPA,CaCDTA,l>PS,rMSA and D-penicillamine

were the nost etfective.For a levei of 1.43 mrol/kg of ZnA^ (LC^g), the

adniinirtraticn of 4. es? cheiating agents at 5:1 nole rat io resulted in a s ig-

nificant eni!afO3i£fi<: of *he survival rate with D-penicillamine,CaEDTA and

toijTPA beim. V*- Tr st effeci.ive. !

•;;••*••••• . U<AC ^*cctiveness vas assesed quantitatively by dividing .;

t i v L'V/. o: Vn± uoated mice by the LOgQ control.The f i r s t groups received !

/ e ax-!6oiiy? a-jp«^<; M/4 t t e i r respective LDCQ values) f ive minutes after ''

-ix ip /*.• ns t ra i : - . i MCerent dosages of zinc acetate (46-2150 mg/kg). '

Jha spcjr»j jroui) receivec 0.9% saline instead of the cheiating agent.CaDTPA j

M3.7), C . L N A ,7 n) , CdCOTA (6.3) and CMSA (5.4) showed the best results. J

D-peniailTrine (1.9) ana Df-PS (1.0) should not be used due to their relative J

hkjft toxic)t>.' '

68

EFFECT OF DTPA AND MUCOSOLVIN TP.1ATMENT ON THELUNG CLEARANCE OF EMPHYSEMATOUS RATS EXPOSED TO144Ce

3. Naffldnyi, A. Gach61yi, I. Szecedi and ;...f-t Varga

National Research Institute for ^adiobrclogy endRadiohygiene, Budapest, Uungarv

One of the main purpose of inhalation radio-toxicology to enhance the elim:* Ttior! c* ra'io-nuclides inhaled by the organic*,;?. lr. t!".l? caseeffective complexforming componp^ (DTPA) is ov^li-able for the reduction of body burden, ^hc e cireno adequate information on the rc}.e of -r-. *rcxistxnglung disease in the retention and rleorj r-.e kinet-ics of inhaled radionuclides. Sines ein h/ rr.a andbronchitis are 3 prominent diseaa-fS in hunsns : idsince mainly mucoiytic agents are ^e'-'Om-^nd^fi forthe mitigation of symptoms, txparimenrs wsrc aimecJto investigate tne affects of N-acetkyi-L-ryctsinc-(Mucosolvin, MC) ar.u DTPA o*i ti<3 T.uco^ili&ry r. Jalveolar clearance 30 well as or. t*';- ellm-ni-ii-.-.of 144ce.

It was stated that in emphyseeir the J.ncna3'» inthe clearance by MC is failed. In ,healthy n'.z^rl^threefold higher elimination of - f<*Ce we3 ac^i vedby a treatment of MC-DTPA combination. Ti;e e'/f?stof this treatment was negligibls in emphysematousrats* According to the results obtained no re ef-fective therapeutic procedures are neeuod ir:emphysema to increase the mucociliary transportand to enhance the mobilization of inhaled !44ce.

THE EFFECT OF ASCORBIC ACID AND DESFERRIOXAMINE

ON THE EXCRETION AND DISTRIBUTION OF 48V.

J.NERUDOVA, P.LEPSt, K.BLAHA. 3r. AND M.CIKRT

IHE, Prague, CSSR.

Female Wistar rat9 (200*20 g) were i.v. in-

jected with 4 8V at the dose of 0.1 ug.kg"1

(0.4 ml; 13 uCi per rat). One hour later ascor-

bic acid (AA) /250 nig.kg" / or desferrioxamine

(DSF) /250 mg.kg"1/ were i.p. injected. Bila(

urine and feces ware, collected for 24 hours

after chelator's administration.

Both compounds tasted significantly decrea-

sed 48V contant in liver (controls 18.4*3.8;

AA 13.1*2.5; DSF 9.215.3 % of administered

dose) and kidney (controls 12.8*1.8; AA 8.8*

-1.5; DSF 5.2t2.4 %) moreovsr DSF also in

brain (controls 0.08*0.01, DSF 0.04*0.03 % ) .

Surprisingly no incraasa in the urinary, fe-

cal and biliary excretion was found.

In the rat hepatocytes, isolated after i.v.48

injection of V, affect of chslstors was stu-

died, AA /250 mg/20 ml/ added to the incuba-48

tion medium resulted in mn increeee of V re-

lease from hepatocytes to the medium.70

In vitro perfused intestnial segments as a tool to study metal-metal and metal-chelator interactions during absorptionKlaus Schumann, Berd ElsenhansWalther Straub-Institut fur Phartnakologie, Miinchen, FRG

The perfusion apparatus according to Fisher and Parsons wasmodified to allow continuous sampling of absorbate from isola-ted perfused intestinal segments. Thus, it Mas possible to de-termine amount and rate of metal transfer. Tissue accumulationand metal transfer velocity correlated significantly (p<0.01)for Fe, Cd, and Cd + nitrilotriacetic acid (NTA). These corre-lations exhibit 3 characteristic features: the tissue accumula-tion level at which the transfer beginns, the ratio between in-crease in tissue accumulation and transfer velocity, and thevalues for tissue accumulation end transfer velocity understeady state conditions. All these parameters differ for Fe,Cd, and Cd • NTA.

Using a luminal concentration of 1 nmol/ml, the intestinaltissue accumulation was k times higher for Cd than for Fe,while the Cd-transfer velocity was only 15-30 % that of Fe-transfer velocity. The transfer of Fe and Cd started when thetissue had accumulated 1 pmol/mg ww and 5 pmol/mg ww respec- htively. The Fe-transfer reached a steady state with a max. ve- \locity of 6 pmol/cm/h and a max. tissue accumulation of 4 pmol I/mg within 90 min, while neither the Cd-transfer and -tissue ?accumulation reached a steady state at this luminal concentra- /tion level. When 1 nmol/ml Cd was added to 1 nmol/ml Fe, the !Fe-transfer decreased to 50 S, while the Cd-transfer was not j-'affected by a 100-fold molar excess of Fe. To prevent hydroxid \formation in the perfusate, Fe was chelated by a 2-fold molar Iexcess of NTA. A 200-fold molar excess of NTA alone increasedCd-transfer velocity to 170 % while the tissue accumulationwas reduced to 35 %. Steady state conditions were net reached..

Influences or chelators and of other metals on metal trans- \fer can thus be characterized in isolated perfused intestinal jsegments. The interaction between metals, chelators and physio-logical Uganda in the intestine can be analysed in the absor-bate as well as in tissue preparations under defined steadystate conditions.

TTHHABY COMPLEXES OP Cu2+ IOHS WITH PYBIDOXAL-5' -

P-'OSPHATE AND HUMAH S2RUK 1LBD1UN

I.I« Stepuro. A.A. Solodunov, A.N. Artsukevich,

M.I. Kukxeah.

Institute of Biochemistry, Byelorussian SSR Academy

of Sciences, Crodno, USSR

When PLP binds to human serum albumin (HSA) in

the molar ratio of 1:1, negative in sign induced

Cotton effect is observed in the ligand absorption

band. The high affinity center is localised in the

second domain at an ^-helical sit* of the protein

molecule. As a result of adding Cu + equimolar con-

centration a new optically active binding alts with

the positive sign of Cotton effect in acidic medium

and the opposite one in alkaline medium is formed

on Lys-4 at the beginning of the polypeptlde chain*

Inversion of the CD spectrum occurs over the same

range of pH of the medium as the change in symmetry

of electric field surroundings (rhombica=*axial) of

the copper ion within the equlmolar ternary complex

HSA:PLP:Cu +. The copper ion Cu * bound to serum

albumin in the most strong center stabilizes aldi-

mlne bonds formed by PLP with 6-HHg group of 4-Lya

and cC-HHg 1-Asp. The stolchiometrlc ratio of the

ternary HSA-PLP-Cu2+ complex is 1:2:1,

72

APPLICATION OF ADJACENCY MATRICES TO THE DESIGNOF COMPLEXING AND CHELATING AGENTS

J.S-flcora, V.EvblDepartment of Pharmacology, Faculty of Medicine,Charles University, Plzen, CSSR

For different types of complexing and chelating•gents the adjacency matrices were formed. Attil* same time graphs of these matrices were con-structed. Raising of the adjacency matrices to• higher power enabled the enumeration of the sooalled scrambling effect. The higher this effectIs, the more labile the given complex or chelateappears and the more suitable it is for detox.i-cation and decorporatlon of radloisotopes. Thepresented method is convenient for screening ofthe ohelating agents.

73

cal Studies on Catecholamic Acid

Efficient Chelating Agent for Metal Mobilization

. £ Tio, X H. Xu, A.M. Van, Z.J. Chen, J.S. Zhang,

V. V. Lie icv : y. Hsleh

Shanghai Institute of Materia Medica, Academia Sinica,

China

Catecholamic acid CCatechol 3,6-bis <methyl-

eneimino diacetic acid>, CBMIDA) is a chelating

{i7'-nt synthesized in our lab. Animal test showed

that '. t wo.', highly effective In detoxicatlon for

JO <N0 )2, NiCi-, MnCl2, CdCl2I ZnSO , CuSO , CoCl ,

CaCl2, moderately effective vs. MgCl2- In mice the

LD-5O n' NiCl2 after CBMIDA was about 9 tiroes of

control, higher than DMSA or EDTA. The agent could

•narkedly enhance excretion of uranium in urine,54 i>

increase the feces and urinary excretion of Mn, ;

and reduce Nl content in blood, lung, Mil in (

heart, liver and kindney. The lethal dose of

UO_<NO >_ was signflcantly increased in rats after

In CBMIDA, there In CBMIDA was more effective than

phosphicine. There were no changes of function and

histology of target organs In dog after 14 daily !

single in CBMIDA, and the Na, K, Ca, Cl contents •

in blood were noraal. Metabolism of I14C)-CBMIDA

In rats and nice Here observed.74

THE BEHAVIOUR OF SUBCELLULAR STRUCTURES OF CEREBC*.LAR CORTEX IN RABBITS CHRONICALLY, EXPERIMENTALLYPOISONED WITH MERCURY AND THEN TREATED BY METHICILLIN OR CUPRENILKrystyna TWARDOWSKA-SAUCHA

Clinic of Internal and Occupational DiseasesSilesian School of Medicine, ZABRZE, Pel ana

Four experimental groups of rabbits w?re .:013a' *with mercury vapour in a concentration of * *i7'V 'for 3 hours daily for 3 months. Immediately sf^arthe exposure one group was killed and 1>.-- r^siing grouns were given Methicillir or Cupit^il revspectively, during 2 weeks. The forth ;v o«. v--»streated.By neant of histochenical methods mito^horuJrlallysosowal and Golgi apparatus murker* werr deftin ceratrallar cortex slices of all -u~up?.The greatest changes in aercury poisoned «nima!were observed in mitochondria.In spite of the Increase of the elimin?•icn jfMercury with urine caused by Methicillin r>r Curnil, no significant improvement in subc<?iKlarstructures affected by mercury war? b

.iot

CHELATES VERSUS METALS IN RAT INTESTINAL MUCOSA

M. VOJTtSEK, M. CIKRT

Institute of Hygiene and Epidemiology, Prague,

CSSR

The aim of thie etudy was to contribute to the

insight into the Mechanise: of chelatee influence

on metal toxicity. Effect of Cd2+, Hg2+ and Zn2*

(chlorides) on energy metabolism of rat intestine

represented by oxygen consumption (measured in

vitro by Clark electrode) was determined. The

same jejun&l mucossl preparate was used for mea-

surement of control value aa well as for the stu-

dy of metal and chelate influences* High doses

of Cd2* or Hg2+ (10~2 to 10"3 mol.l"1) inhibited j

mucosrI tospiration, Zn + had no effect* |

The infitence of ethylenediaminotetraacetic i

ccicJ iEDTA} and bis(2-hydroxyethyl)dlthlocarba-

mate (D6DTC) on respiration changes was tasted.

EOTA had no effect on inhibition of reepiration

by Cd2+ (10"2 to 10"3 •ol#l"1) but equimolar do-

ses of DEOTC abolished inhibition. Hg2+ (10~2

mol.l"1) irreversibly inhlbitsd respiration, all

lower do388 could be compensated by DEDTC and

respiration was fully restored.

76

ON THE PROTECTIVE EFFECT OF COPPER ON ACCUTETOXICITY OF CISPLATINUM IN MICED. WAITZOVA*. F. JELJNEK. V. EY3LState Institute for Drug Control, Prague, Oept- ofPharmacology, Medical Faculty. Charles University,Pilsen, Czechoslovakia

A protective effect of preaa.Tfini^trs tir of CJ inacute intoxication with ci&-diasT.isina?ii:.MGropi«itir;u3(Platidiam, Lachema) in th? experiments or sn*c*described in the literature (1) w:i? not atzi/wsd.Under the same experimental condition tba ~rotectivteffect had neither Mn or Cr. V.irDnolopjc: r.-iangesinduced by cisplatinum in k4dneyt inc. iie >were not influenced by a single adwir.istretic . ofCu as well.

1. A. Naganuma, M. Satoh, Y. Xoyam*, N.Toxicology letters, 24 (1985) 203-207

77

ON THE MECHANISM OF CYTOCHROME P-450 DEPENDENT FORMATION OF

REACTIVE METABOLITES 6* SOME THIOL COMPOUNDS.

S.Venev.M.Kadi iska.F.Jahn.D.Muller,W.Kiinger,Ts.Stoytchev.Inst .Physio! . .Bulg.Acad.Sci . .Sof ia,Bulgar ia and Ins t . Pharmaco-"togj and Toxicology, Jena, GDR.

:.';T r revious studies have snown that d i f fe ren t a lky l der iva--•/£<; -if J i t l i iocarbonic acids/xanthogenates/act as chea t i ngagents ,n neavy metal in tox icat ions and i r h i b i t l i v e r dru j meta-bolism D/ cyt,ochrome P-450 dependent formation of react iveinetabo'iitss. Thus they behave "like "suic ide" cylochrome P-460substrates.

In the oreserit study we t r i ed to f ind which cytochrome P-450subspecie: is involved in xarcthogenates metabolic ac t i va t i on .The in v i t r j k i ^eUc parameters of ethylmorphine-N-^emethylation•:"M/, 7-etho:»ycciiiiiar ine-O-deethylation /EC/ and 7-ethuAyreso -- j f i t i f ' -O- i f j i . thy la i ion /ERF/ in rat l i v e r 9000 x g supernatantsfrom cor.* 31 , ohenoberbitsl /PB/ and beta-naphtoflavone /BNf-/were studied i i i ^he presence of d i f f e ren t concentrations ofpo*.»$•• ••'•m ettv-'lxantiK-^'Tiate /PEX/, potassium butyl xanthogenate/B> ' -fid soJit-m diethyldithiocarbamate /D :.K/. In control ratsPEX, BX ar^ D" inh ib i ted noncompetitively EC whOe EM a;.d ERFv/ere i ih ib i i ' .a only i ' trie high concentration/10" JM/. PB indue-t o . , ^vor 'gr , ttv^ula^ed the noncompetitive inhib i tory ef fectu r PEX em., RX f>-jt recuced that of DDC on EC,ERF inh ib i t i onk.ss s 1 i9.vt"; r change^ a-\i the i nh ib i t i on of EM tended towardsc. mixed .ypo. Aftpr SNf induction the i / ih ib i tory e f fec t of PEXBX .i-ui DD'J di dp earsd for a l l three substrates used.

It. ,s concluded that l i v e r metabolic act ivat ion of xantho-geii-tos '$ cicv!ieved by a PB - inducible cytochroine-P-150-sub -

.L^ wi*:v; a high a f r i n i t y fo r 7-ethixycoumarine.

78

IONAL CHANGES AFTER APPLICATION OF FCOL ANDITS MODIFICATION BY EDTA: STUDY IN IRRADIA-TED AND NON-IRRADIATED RATS

D.^ERNICEK, J.VASK8, M. DOSTAL, I.AHLERS+,E.URBJLNEK

Dept. Pathoph.ysi.ol., Med. Fac. . J.E. PurkyngUniv.. Brno; Dept. Gen. Biol., Fac. Nat. Sex.P.J. Safdrik Univ., KoSice, CSSF

Continously gamma irradiated rats exposed todaily doses of 0.096 Gy during a 50 days pe-riod were subjected to a treatment with car-diotoxic doses of NaoHPDj, + 9-alpha-fluorocor-tisol (FCOL) on the 25 day after the end ofIrradiation. FCOL in the same dosis was appli-ed to non-irradiated rats, too. The total con-tents of Ca , Na ,K ions (in mmol/kg of drysubstance) as well as K/Na index were studiedin the myocardium and samples were taken frommuse* vastus lateralis, kidneys, liver andspleen. The mortality of animals was assessed.The application of FCOL (cardiotoxic dosis)caused the significant increase of Ca andNa and the decrease of K/Na index only inthe myocardium of both irradiated and non-ir-radiated rats. The administration of Na^-EDTA(2 mg/lOO g twice a day s.c.) had its partialproteotive influence on ionic changes in themyocardium of both irradiated and non-irradia-ted rats, provoked by FCOL and decreased signi-ficantly mortality of our animals (more evidentIn Irradiated rats).

79

a -2nd INTERNATIONAL SYMPOSIUM —

CHELATING AGENTS IN PHARMACOLOGY, TOXICOLOGYAND THERAPEUTICS

P i 1 s e n , 12. - 14. 8. 1987

F I N A L P R O G R A M M E

o r g a n i z e d by

THE CZECHOSLOVAK MEDICAL SOCIETY 3. E. PURKYNEThe Czechoslovak Pharaacological Society

in c o o p e r a t i o n w i t h

THE DEPARTMENT OF PHARMACOLOGYFaculty of Medicine, Charles University, PilsenandTHE INSTITUTE OF HYGIENE AND EPIDEMIOLOGYPrague

ORGANIZING COMMITTEE

V. EYBL President0. KAITZOVA Scientific Secretary0. CAISOvA MeabersM. CIKRTH. KOUTENSKAJ. KOUTENSKYJ. SYKORAA. ZECHMEISTERZ. VRANA SecretariatR. TICHA

-1-

GENERAL INFORMATION

PLACE AND DATE OF THE SYMPOSIUM

The meeting will be held at the House of Culture (Dum kultury ROH)MoskevskS ul., Plzen - phone: 224742, from August 12 to 14, 1987.The scientific programme will start on August 12 at 8.40 a.m. andfinish on August 14 approx. 6 p.m.

ADDRESS OF THE SECRETARIAT ANO REGISTRATION OFFICEbefore and after the symposium

Czechoslovak Medical Society JEPGHELATING AGENTSP.O.Box BB

CS-120 26 PRAGUE 2

Phone: 297271 Cable: purkynemedical praha Telex: 121293

during the symposium

Students Hall of ResidenceBolevecka* 30

CS-301 66 PLZEN-lochotln

Phone: 33814-6

OFFICE HOURS

TUESDAY August 11 2.00 p.m.-10.00 p.m.HONESOAY-FRIDAY August 12 - 14 8.00 a.m.-12.00 a.m.ACCOMMODATION AND HEALSAccommodation for Symposium Members and their Accompanying Persons '•will be provided in single and double rooms with shower at the jStudents' Hall of Residence. Breakfasts will be served at the Isame place, lunches in the House of Culture and supper at the Arestaurant "GERA", Sverdlovski St. (close to the Students' Hallof Residence). 'SPECIAL BUS SERVICE ^

There will be buses for transport of Symposium participants from |Pilsen to Prague. Time of departure from Pilsen will be 7.00 a.m. l

and time of arrival at the Prague airport approx. 9.00 a.m. on 15.8. jSpecial buses will take the participants from the Students Hall !of Residence to the Symposium Building every morning at 7.45 a.m.

SOCIAL PROGRAMME- Welcome Reception j

- Half Oay Excursion to Western Bohemia (incl. isupper)orKladruby Monastery

- Farewell Party

12.08.- 9.00 a.m. - Pilsen Sight-seeing Tour

13.08.- 9-00 a.m. - Excursion to the Pilsner Brewery

14.08.- 8.30 a.m. - Kozel Castle

12.

13

14

.08.-

.08.-

.08.-

LADIES

7.

1.

7.

,30

.30

.30

PP.

P

,m

.m

.mPROGRAMME

INFORMATION FDR SPEAKERSSLIDES5 x 5 cm slides may be shown during the presentation.

Slides have to be arranged upside down and numbered successivelyin the right upper corner. The box containing slides must bemarked clearly with author s name.

Please submit your slides to the respective desk at the Symposiumplace oefore opening of the session and collect them immediatelyat the end of it.

SYMPOSIUM LANGUAGE

English without simultaneous translation.

TIMING OF PAPERS

Speakers are requested to keep strictly the appointed time so thatthe programme time table can be adhered to.

INFORMATION FOR AUTHORS OF POSTER PRESENTATIONS

Your poster presentation should be mounted on the assigned boardfrom 8.00 to 8.30 a.m. on August 12 and removed until 6.00 p.m.August 14.

The presentation board consists of a soft desk which will acceptpins. The available area is 1 x 1 m. Pins offered on the spot.

Presenters must be in attendance at their posters for discussionon August 14 from 2.00 to 4.30 p.m.

Posters will be numbered in accordance with the programme.

ACKHPtHEPGEHENTOrganizing Coaaittee wish to express their thanks to the firi

TSUMWtA JUNTEMDO. Inc.. TOKYO. Japanrgi

flrand gratefully acknowledge generous support to both scientificand social event* of the Syapoaiu*.

-*-

SCIENTIFIC PROGRAMME

August 12, 1987

B.QO - B.30 Posters-setting up time

ROOM "A"

8.40 WELCOME

Session 1

Chairmen: G. J. KONTOGHIORGHES, A. E. MARTELL

9.00 - 0. M. TAYLOR

Can in vitro methods reliably predict the efficacy in vivo

of new chelators?

9.Z5 - W. LAASS

Multivariate analysis of effects of selected chelating

agents and relevant structure-activity relationship

V.5Q - H. H. PETER

Hew developments in iron chelation therapy

10.15 - Break

Session 2

Chairmen: W. IAA5, 0. M. TAriOR >.

10.45 - K. B. 0 HARE, R. OUNCAN, P. KQPECKOVA, J. KOPECEK 1

Development of soluble synthetic polymers as a potential

drug delivery system for the treatment of iron overload j

11.10 - G. J. KONIOGHIORGHESi

Orally active •<-- ketohydroxypyridine iron chelatorsintended for clinical use

11.35 - A. £. MARTELL

The design and use of chelating agents for the formation

of radiopharnaccutical diagnostic agents

12.00 - 13.30 Lunch break

Session 3

Chairmen: H. V. APOSHIAN, S. K. TANOON

13.30 - R. MULLER

Preparation and characterisation of chelate ligands of

biphenyl and derivable compounds

-5-

13.55 - H. SPIES

Diagnostic use of Technetium-99 m chelates

14.20 - A. VERBON, P. j. VAN OER SCHAAR Jr., P. J. VAN OER SCHAAR

PseudothrombocytDphenia, an EDIA - induced artifact

14.45 - H. V. APO5HIAN, R. M. MAIORINO, 0. F. PERRY

Metabolic studies of meso-DMSA in humans

15.10 - H. L. HAUST, 0. D. SPENCE, H. POON, F. PETER

Long-term treatment of lead (Pb) poisoning with dimercapto-

succinic acid (0M5A)

15.35 - Break

Session 4

Chairmen: M. CIKRT, H. L. HAUSI

16.00 - S. K. TANDDN

Combination therapy: A better approach to chelation in

metal intoxication

16.25 - «. BLUMER

Cancer prevention by chelation therapy

16.50 - 5. 3. HANG. J. LIU. I. SHI

Chelators in the therapy of occupational metal intoxi-

cation in China

17.15 - fl. r*NG

A comparison of the effects five cuprurctic drugs on the

turnover of copper in hepatolenticular degeneration

17.40 - T. T. HSIEM, K. I. CHEN

Hen chelating agents for detoxication of metal poisoning

ROOM -B"

Sesslon 5

WORKSHOP ON INTRAVENOUS EOTA CHEUATION THERAPY FOR ATHEROSCLEROSIS

(In cooperation with the Internationa) Chclation Research Foundation)

Chairaen: M. RUBIN, A. ZECHMEISTER

13.30 - E. M. CfUHIOH

Effectiveness of intravenous EOTA chelation therapy for

atherosclerosis

-6-

13. 55 - H. R. CASOORPH

Objective evidence of the efficacy of chelation therapy

by radionuclide studies in patients with heart and brain

disorders

14.20 - 0. BRUCKNEROvA

Chelation therapy in occlusive arteriosclerosis

14. ib - 7. MATTAR

Chelation Brazilian way selection of patients and clinical

aspects

15.10 - C. H. FARR

Possible therapeutic value of intravenous hydrogen peroxide

15.35 - Break

Chairaen: H. R. CASDORPH, E. M. CRANTON

16.00 - fl. LEV, R. HENASHE, J. BUSH, M. LEV

Physiologic indications and contraindications for EDTA

chelation in arteriosclerosis obliterans

16.15 - A. ZECMMEISTER, M. RUBIN

£OfA therapy of intermittent claudication

16.50 - M. RUBIH, A. ZECMMEISTER

The rationale for EOT* therapy in atherosclerotic cardio-

vascular disease

August 1), 1907

ROOH "A"

Session £

Chairmen: G. HEHNICHAUSEH, M M. JONES

8. 15 - 0. ANDERSEN

Chelation of cadatiu* in vivo

8. 10 - J. ALEXANDER, 3. AASETH

Effects of coitplexing thiols on biliary excretion of lead

in the rat

-7-

9. 03 - H. TJALVE, S. JAS1M, J. G0TT0FREY, K. BORG

Chelate-induced changes in metal disposition.- studies on

dithiocarbamates, pyridinethiones, xanthates and dithio-

phosphates in rodents and in fishes

9. 30 - C. W. MAYS, G. N. TAYLOR, R. 0. LLOYD, F. W. BRUENGER

Decreasing the risk from Pu-239 and Am-241 via chelation

9. 55 - Break

Session 7

Chairmen: J. AASETH, 0. ANOERSEN

10.20 - B. FICHTL, H. KREPPEL, F. X. REICHL, W. FORTH

Lack of effectiveness of 0-penicillamine in acute experi-

mental arsenic poisoning

10.45 - G. MENNIGHAUSEN, 3. MERKORO, G. KRdNING

Interactions of meso-2,3-dimercaptosuccinic acid (DMSA)

with dialkyltin compounds

11.10 - S. G. SCHAFER

Treatment of methylmercury poisoning by subchronic adminis-

tration of sodium 2,J-dimarcapto-1-sulfonat (OMPS) h

11.30 - 12. 30 - Lunch brsafc /

kAugust 1«, 1987 >,

ROOM -A" ]Sassion 0

Cftairawn: I. B. AFANASIEV, S. GABOft

B. 15 - H. VAN OER GOOI, H. 0. CAIS5ER, M. A. H. OE ZWART,

H. IIHMERMAM

Tha antiftycoplasaal activity of 2,2- bipyridyl analogues

in the presence of copper

8. 40 - N. A. 006RYUIMA, A. M. AGRANOVITCH, E. V. ISAEVA,

I. I. MARTYftEIIKO

The investigation of complex formation in the systems

FeCl^ - CuCl2 - pyridoxal - glucosamine with the mathema-

tical wooel method

-B-

9. 05 - L. MORPURGO, E. AGOSTINELLI, M. T. GRAZIANI, I. AVIGUANO,

B. M0N00VI

Inactivation of copper oxidases by chelating agents

9. JO - A. ZECHMEISTER, P. MATONOHA, E. HAOASOvA, M. OOSTAL,

I. SvfZENSKA"

The effect of EOTA, OTPA, verapamil and calcitonin on the

metabolism of Ca + and some other bivalent (Pb, Cu, Ni,

Cd, In, Fe, Hn, Mg) and monovalent (K, Na, P) ions

9. bb - E. A. YURIEVA, Y. E. WELTISCHEV, N. V. ALEXEEVA,

0. G. ARCHIPOVA, H. H. DIATLOVA

Oiphosphonate pharmacological properties when treating

soft tissue calcification

10.20 - Break

Session 9

Chairmen: E. A. YURIEVA, L. MORPURGO

10.45 - A. I. DOROZHKO, A. V. BROOSKII, I. 8. AFANASIEV J

Chelating and antioicidant effects of rutin on lipid •

peroxirlation in liposomes and microsomes

11.10 - S. R. R1BAR0V, L. C. 8EN0V, 0. H. MONOVICM

Is thiol antidotes-induced chemiluminescence associated

•cith production of activated oxygen? ,

11.35 - 1. C. BENOV, 0. H. MONOVICH, I. C. BENCHEV *

Effect of OMPS and 0-penicillatnine on the level of lipid X

peroxidation products in metal poisoned rats

12.00 - S. GABOR, M. BOTOC, A. KQVATS

Effect of OMPS and OHSA on lead-induced lipid peroxidation

in rat liver and kidney

12.00 - 13.JO - Lunch brstk

14.00 - 16.30 - Poster session

PRESENTERS MUST 8E IN ATTENDANCE AT THEIR POSTERS FOR DISCUSSION

AT THI5 TIME

16.30 - ROOM "A" - Closing ceremony

-9-

P O S I E R S

1. D. ANDERSEN

Effects of disulfiram and its metabolites on cadmium toxico-

kinelics

2. H. AONO, 5. ARAKI

Behaviour of heavy metals in plasma, erythrocytes and urine

following intravenous infusion of Ca EDTA in metal workers

J. M. M. APOSHIAN, H. V. APOSHIAN, J. L. DOMINGO, J. M. LLOBET

ZHENG WEI, R. C. OART

Radon decay products: DMPA decreases tissue polonium - 210

«. M. A. BASINGER, M. M. JONES, M. A. HOLSCHFR, W. K. VAUGHN

Antagonists for acute oral cadmium chloride intoxication

5. 0. BIITNEROVA, K. BLAHA Jr., M. CIKRT, A. BABICKY

The effect of bis (hydroxyethyl) dithiocarbamate on the

excretion of Ni in rats

6. K. BLAHA Jr., M. CIKRT, L. KASPAfiOvA, M. M. JONES

I fie effect of simultaneous administration of two dithiocarba- .,

nates on Cd excretion in rats i

7. V. 8. BRAIOE, V. GRILL, G. DE18ELL0 |

Calciua EOIA toxicity in the rat: ultrastructural effects on

skin collagen (

B. 0. CAISDVA, V. EY8L r

The effect of cadnlu* and chelating agents on CuZn superoxide

dissutase activity in liver of nice

9. H. CIKRT, P. J.EPSI, K. BV.AHA Jr.. L. KAfiPAROVA, 0. BITTNEROVA

The effect of desferrioxainine on distribution and excretion

of Al in rats drinking water containing Al-citrate

10. J. L. O0MING0, A. ORTEGA, 3. M. LLOflET, J. L. PATERNAIN,

J. CORBELLA

Conparison of the antidotal efficacy of chelating agents upon

acute toxicity of strontium in nice

11. V. EVBL, J. AASETH, M. KOUTENSKA, J. KOUTENSKY, J. SYKORA

Desferrioxamine and CaDTPA in indium intoxication

-10-

12. M. FRELLA, N. GARRICA, A. IZQUIERDO,0. R. WILLIAMS

Computer simulation of the ability of 2-mercapto-3-phenyl-

propenoic acid to mobilize the l.m.w. fraction of zinc (II)

in blood plasma

13. S. FUKUDA

Toxicity of OIPA administered intravenously or orally in

rats and beagles

14. A. G A C H A L Y I , J. NAMfNYI, I. 5ZEGEDI, P. L. VARGA

Dynamics of whole body retention of repeated internal95 144contamination with Nb and Ce radioisotopes in mice

15. M. JAKUBDWSKI, 3. INDULSKI

Possibility of renal dysfunction as a result of exposure

to cadmium

16. 5. G. JONES, M. M. JDNES, M. A. HOLSCHER, W. K. VAUGHN

The effect of zinc on the dithiocarbamate - induced mobili-

zation of aged cadmium deposits in mice

17. V. KOBRIE, M. CIKRI. J. HAVRDOVA", E. EFFENBERGEROvA,

E. MlftEJOVSKA, K. 8LAHA Jr., J. HURYCH, H. M. JONES I

Protective effect of diethyldithiocarbamate or metallo- J

thioneins on cadmium - induced lung damage in rats <

IB. V. KOBRLE, 3. HUP.YCH, J. SLABY, P. FRlC, E. EFFENBERGEROVA, '.

R. HOLUfiA, E. MlftEJOVSK* •

Response of rat lung tissue following cadmium intoxication

19. J. KOUTEMSKV, H. KDUTENSKA, V. EYBL

Conparison of MgEOIA and Na^EDTA • acute toxicity and excretion

via the urine

20. «. LAASS

Examples for nultivariate of selected chelating agents andrelevant structure - activity relationship

21. S. LIOCHEV, I. FRIDOVICH

The oxidation of NAOH by vanadate plus sugars

22. J. H. LLOBET, A. BOSOUE, M. T. COLOMINA, J. L. 00MING03. C0R8ELLA

The protective action of chelating agents in experimental zincpoisoning

-11-

23. J. NAME^YI, A. GACHAlYI, I. SZEGEOI, I. P. VARGA

Effect of DIPA and mucosolvin treatment on the lung clearance14*

of emphysematous rats exposed to Ce

24. J. NERUOOVA, P. LEPSf, K. BLAHA Jr., M. CIKRT

The effect of ascorbic acid and desferrioxamine on the ex-A H

cretion and distribution of V

25. K. SCHUMANN, B. ELSENHANS

In vitro perfused intestinal segments as a tool to study

metal-metal and metal-chelator interactions during absorption

26. I. I. 5TEPUR0, A. A. S0L00UN0V, A. N. AilTSUCHEVICH, M. I. KUKRESH2

Ternary complexes of Cu ions with pyridoxal - 5 - phosphateand human serum albumin

27. 3. SYKORA. V. EYBL

Application of adjacency matries to the design of complexingand cheiating agents

28. I. SZEGEOI, A. G A C H A L Y I , J. NAM£NYIf P. L. VARCA

Effect of lavage fluid on the removal of radiocerium from thelung

29. Z. Q. TAO, X. H. XU, X. M. YAN, Z. J. CHEN, J. S. ZHANG,

V. Y. LIANG, Y. Y. HSIEH

Pharmacological studies on catecholamic acid - an efficientcheiating agent for metal mobilization

30. K. TMAROOHSKA-SAUCHA

the behaviour of subcellular structures of cerebellar cortexin rabbits chronically, experimentally poisoned with mercuryand then treated by methicillin or cuprenil

31. M. VOJTf§EK, H. CIKRT

Chelates versus metals in rat intestinal mucosa

32. 0. MAITZOVA", F. JELlNEK, V. EYBL

On the protective effect of copper on acute toxicity of cis-

platinum in mice

-12-

33. 5. YANEV, M. KADIISKA, F. JAHN, 0. MtJLLER, W. KLINGER,

T. STOYTCHEV

On the mechanism of cytochrome P-450 dependent formation of

reactive metabolites by some thiol compounds

34. D. 2ERNf£EK, J- VASKO, M. DOSTA"L, I. AHLERS, E. URBA"NEKIonal changes after application of FCQL and its modificationby EDTA: Study in irradiated and non-irradiated rats

-13-