The renal carcinogenic effect of Merpafol in the Fischer 344 rat.

Three groups of Fischer 344 rats were fed Merpafol (Makhteshim, Israel), an agricultural fungicide, in increasing concentrations for a period of 2 years. A control group was maintained under identical conditions, but without the addition of the fungicide in the diet. A range of nonneoplastic and neoplastic lesions were observed in the kidneys of rats fed Merpafol. The histogenesis of the renal tumors is discussed in relation to chemical-induced epithelial hyperplasia and cystic tubular dilation. Comparative aspects of renal cyst development and carcinoma in humans are also discussed.