EFFECT OF SUPEROXIDE-DISMUTASE AND CATALASE ON THE NEPHROTOXICITY INDUCED BY SUBCHRONICAL ADMINISTRATION OF OCHRATOXIN-A IN RATS

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus ochraceus as well as other molds. It is a natural contaminant of mouldy food and f eed. OTA has a number of toxic effects, the most prominent being nephr otoxicity. Futhermore, OTA is immunosuppressive, genotoxic, teratogeni c and carcinogenic. OTA inhibits protein synthesis by competition with phenylalanine in the phenylalanine-tRNA aminoacylation reaction. Rece ntly, lipid peroxidation induced by OTA has been reported, indicating that the lesions induced by this mycotoxin could be also related to ox idative pathways. It was then interesting to study effects of the supe roxide dismutase (SOD) and catalase on the nephrotoxicity induced by O TA in rats. The two enzymes (20 mg/kg body weight each) were given to rats by subcutaneous injection, every 48 h, 1 h before gavage by OTA ( 289 mu g/kg b.w. every 48 h), for 3 weeks. SOD and catalase prevented most of the nephrotoxic effects induced by ochratoxin A, observed as e nzymuria, proteinuria, creatinemia and increased urinary excretion of OTA. Altogether these results indicate (i) that superoxide radicals an d hydrogen peroxide are likely to be involved in the damaging processe s of OTA in vivo, (ii) that SOD and catalase might be used for prevent ion of renal lesions in cases of ochratoxicosis.