Carcinogenicity of ochratoxin A in experimental animals.

The carcinogenicity of ochratoxin A, a naturally occurring mycotoxin of the fungal genera Aspergillus and Penicillium, was evaluated in three strains of mice and in one strain of rats. The kidney, and in particular the tubular epithelial cells, was the major target organ for ochratoxin A-induced lesions. In male ddY and DDD mice, atypical hyperplasia, cystadenomas and carcinomas of the renal tubular cells were induced, as were neoplastic nodules and hepatocyte tumours of the liver. In B6C3F1 mice, tubular-cell adenomas and carcinomas of the kidneys were induced in male mice, and the incidences of hepatocellular adenomas and carcinomas were increased in male and female mice. In male and female F344 rats, ochratoxin A induced nonneoplastic (degeneration, karyomegaly, proliferation, cytoplasmic alteration, hyperplasia) and neoplastic effects (adenomas, and carcinomas with metastases) in the kidneys; the incidence of fibroadenomas of the mammary glands was also increased in female rats. Other studies on ochratoxin A were considered inadequate for evaluating the presence or absence of a carcinogenic effect; however, these are mentioned and referenced below. The collective experimental findings, together with accumulating evidence in humans, forecast further toxic and carcinogenic effects in humans exposed to ochratoxin A, mainly via foodstuffs.