Polycystic changes in rat kidney induced by biphenyl fed in different diets

Groups of rats were fed biphenyl at various dose levels in a semisynthetic diet and in a commercial chow. The effect levels for induction of polycystic kidney lesions were established by means of urinalysis, organ weight changes, light and electron microscopy, and enzyme histochemistry. The no-effect level, was less than 50 mg/kg bw./day and 300 mg/kg bw./day, when feeding the semisynthetic diet and the commercial chow respectively. This difference in effect level due to the diet is an indication that the diet is of great influence on the results of toxicological experiments.