Veterinary Science Communications

, Volume 1, Issue 1, pp 349–358

Contribution of pharmacokinetic studies to mycotoxicology—Ochratoxin A

  • P. Galtier
European Community Preview Article

Abstract

A pharmacokinetic study of ochratoxin A in rats has demonstrated the binding of the toxin to serum albumin and its presence in all organs investigated. The acidic properties of the mycotoxin explain its absorption from the stomach and the fact that it binds to some macromolecules.

Ochratoxin A is converted into the less toxic ochratoxin ∞ by the bacterial microflora present in the rat caecum and in rumen liquor, and this product of hydrolysis has been recovered from urine and faeces. However, oxhratoxin A itself is excreted in the milk of rabbits.

Using the example of ochratoxin A, the author discusses the value of such investigations in the study of the contamination of the human food chain.

Kurzfassung

Das pharmako-kinetische Studium des Ochratoxins A an Ratten zeigt, dass das Toxin an das Albumin des Plasmas gebunden wird; sein Nachweis gelang in allen untersuchten Organen. Die sauren Eigenschaften des Mycotoxins machen eine Resorption im Magen sowie die Bindung an einige Makromoleküle verständlich. Das Ochratoxin A wird durch die bakterielle Mikroflora des Caecums der Ratte als auch durch Pansensaft zu Ochratoxin ∞ umgewandelt. Dieses Hydrolysat ist in Harn und Fäces der Tiere nachweisbar. Ochratoxin A jedoch wird nur mit der Milch des weiblichen Kaninchens ausgeschieden.

Im Anschluss an die Beispiele diskutiert der Autor des Interesse dieser Studien bezüglich einer Kontamination in der Ernährungskette des Menschen; immerhin geben jene Ergebnisse Anlass genug für weitere gründliche Untersuchungen.

Resume

L'étude pharmacocinétique de l'ochratoxine A chez le Rat démontre la liaison de la toxine avec l'albumine plasmatique et sa présence dans tous les organes examinés. Les propriétés acides de la mycotoxine permettent d'expliquer son absorption gastrique et les liaisons avec certaines macromolécules. L'ochratoxine A est transformée en ochratoxine ∞ moins toxique par les microflores du caecum de Rat et des liquides de rumen. Ce produit d'hydrolyse est retrouvé dans l'urine et les fèces des animaux; toutefois, l'ochratoxine A est excrétée seule par le lait de la lapine.

A partir de cet exemple, l'auteur discute de l'intérêt de telles études à propos du problème de la contamination de la chaîne alimentaire de l'Homme et justifie l'approfondissement de recherches complementaires.

Riassunto

Lo studio farmacocinetico dell'ochratossina A nei ratti mette in luce la relazione esistente fra la tossina e l'albumina plasmatica, nonché la sua presenza in tutti gli organi esaminati. Le proprietà acide della micotossina spiegano il suo assorbimento gastrico ed i suoi legami con talune macromolecole. L'ocratossina A è trasformata in ocratossina ∞ meno tossica, dalla microflora batterica dell'intestino cieco del ratto e dal succo gastrico. Questo prodotto idrolitico è presente nell'urina e nelle feci degli animali; peraltro l'ocratossina A è eliminato soltanto attraverso il latte della coniglia.

Basandosi su questo esempio, l'autore esamina l'interesse di tali studi in relazione al problema della contaminazione della catena alimentare umana e motiva la necessità di ulteriori ricerche.

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References

  1. Chu, F.S., 1971. Interation of ochratoxin A with bovine serum albumin. Arch. Biochem. Biophys., 147: 359–366.Google Scholar
  2. Chu, F.S., 1974. Studies on ochratoxins. Crit. Rev. Toxicol., 2: 499–524.Google Scholar
  3. Chu, F.S. and Chang, C.C., 1971. Sensitivity of chicks to ochratoxins. J. Ass. off. anal. Chemists, 54:1032–1034.Google Scholar
  4. Elling, F., Hald, B., Jacobsen, C. and Krogh, P., 1975. Spontaneous toxic nephropathy in poultry associated with ocharatoxin A. Acta path. microbiol. scand., A, 83: 739–741.Google Scholar
  5. Galtier, P., 1974a. Devenir de l'ochratoxine A dans l'organisme animal. I. Transport sanguin de la toxine chez le rat. Ann. Rech. Vétér., 5: 311–318.Google Scholar
  6. Galtier, P., 1974b. Devenir de l'ochratoxine A dans l'organisme animal. II. Distribution tissulaire et élimination chez le Rat. Ann. Rech. Vétér., 5: 319–328.Google Scholar
  7. Galtier, P. and Alvinerie, M., 1976. In vitro transformation of ochratoxin A by animal microbial floras. Ann. Rech. Vétér., 7: (in the press).Google Scholar
  8. Galtier, P., Baradat, C. and Alvinerie, M., 1976. The mammary excretion of ochratoxin A in rabbit female I.U.P.A.C. Symposium, Mycotoxins in Foodstuffs, Paris, Sept. 16–18 (in preparation).Google Scholar
  9. Hald, B., and Krogh, P., 1972. Ochratoxin residues in bacon pigs, I.U.P.A.C. Symposium, Control of Mycotoxins, Kunglav, Sweden, Aug, 21–22.Google Scholar
  10. Hutchinson, R.D., Steyn, P.S. and Thompson, D.L., 1971. The isolation and structure of 4-hydroxyochratoxin A and 7-carboxy 3, 4-dihydro —8-hydroxy — 3-methylisocoumarin fromPenicillium viridicatum. Tetrahedron letters., 43: 4033–4036.Google Scholar
  11. Jacobs, M.H., 1940. Some aspects of cell permeability to weak electrolytes. Cold Spring Harbor Symp. Quant. Biol., 8: 30.Google Scholar
  12. Meisner, H. and Chan, S., 1974. Ochratoxin A, an inhibitor of mitochondrial transport systems. Biochemistry, 13: 2795–2800.Google Scholar
  13. Nel, W. and Purchase, I.F.H., 1968. The fate of ochratoxin A in rats. J.S. Afr. Chem. Inst., 21: 87–88.Google Scholar
  14. Pitout, M.J., 1968. The effect of ochratoxin A on the glycogen storage in rat liver. Toxicol. Appl. Pharmacol., 13: 299–306.Google Scholar
  15. Pitout, M.J., 1969. The hydrolysis of ochratoxin A by some proteolytic enzymes. Biochem. Pharmacol., 18: 485–491.Google Scholar
  16. Sawhney, D.S., Vadehra, D.V. and Baker, R.C., 1973. The metabolism of14C aflatoxins in laying hens. Poultry Sci., 52:1302–1309.Google Scholar
  17. Van Walbeek, W., Moodie, C.A., Scott, P.M., Harwig, J. and Grice, H.C., 1971. Toxicity and excretion of ochratoxin A in rats incubated with pure ochratoxin A or fed cultures ofPencillium viridicatum. Toxicol. appl. Pharmacol., 20: 439–441.Google Scholar
  18. Wogan, G.N., Edwards, G.S. and Shank, R.C., 1967. Excretion and tissue distribution of radioactivity from aflatoxin B1 14C in rats. Cancer Res., 27: 1729–1736.Google Scholar
  19. Yamazaki, M., Suzuki, S., Sakakibara, Y. and Miyaki, K., 1971. The toxicity of 5-chloro 8-hydroxy 3,4-dihydro 3-methyl isocoumarin 7-carboxylic acid, a hydrolyzate of ochratoxin A. Jap. J. med. Sci. Biol., 24: 245–250.Google Scholar

Copyright information

© ESCS, EEC, EAEC 1977

Authors and Affiliations

  • P. Galtier
    • 1
  1. 1.Laboratoire de Pharmacologie-Toxicologie INRAToulouse(France)

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