Effects of photomirex and mirex on reproduction in the rat

Abstract

Groups of weanling male and female rats were fed diets containing photomirex at levels of 0, 2.5, 5.0, 10, 20, or 40 ppm or mirex at 5.0, 10, 20, or 40 ppm for a period of 91 days prior to mating, 15 days during mating, and throughout gestation and lactation. Females fed 40 ppm photomirex or mirex diet showed a significant decrease in weight gain but not in food consumption. Both chemicals at levels of 5.0 ppm and up resulted in a decreased incidence of females showing sperm in vaginal smears. While the litter size was decreased in all treatment groups, the survival indices of pups were affected only by 40 ppm photomirex and 20 ppm mirex. On necropsy, enlarged livers were observed in adult females treated with 40 ppm of photomirex or mirex. Hepatic microsomal aminopyrine demethylase activities were increased in all treated groups of females as well as their offsprings. Minor biochemical changes in serum included elevated levels of cholesterol and total protein of female rats fed 40 ppm photomirex. Residue analysis showed that both chemicals accumulated in a dose-dependent manner in the fat and livers of the adult females, and in the livers of rat pups. None of the hematological parameters were affected by treatment. Histopathologic changes were observed in the livers and thyroids of mothers and pups from all treatment groups. Both photomirex and mirex caused cataract formation in the pups.