ACCUMULATION OF DIETARY METHYLMERCURY IN THE TESTES OF THE ADULT BROWN-NORWAY RAT - IMPAIRED TESTICULAR AND EPIDIDYMAL FUNCTION

The widespread consumption of fish containing elevated concentrations of methylmercury has prompted concern over the health effects of such a diet. Previous studies with rodents have indicated that exposure to dietary mercury (Hg) impairs male reproductive health. However, advers e effects were observed following doses in the range of milligrams per kilogram of body weight, whereas typical human consumption in the Uni ted States is in the range of micrograms per kilogram of body weight. This study examined the effects of dietary Hg on male rats using level s of the metal that are more similar to those typically consumed by hu mans. For 19 weeks, adult male Brown Norway rats were administered met hylmercury twice weekly at 0.8, 8.0, or 80 mu g/kg. Intratesticular te stosterone levels in the high-dose group were reduced by 44%. suggesti ng that steroidogenesis in these animals was dramatically impaired. Al though sperm production was not significantly affected, numbers of spe rm in the cauda epididymides of the high-dose group were reduced by 17 %. Furthermore, there was a negative correlation between fertility and testicular Hg content. These results raise the possibility that expos ure to Hg at levels consumed by humans may result in steroidogenic imp airment. reduced sperm counts, and fertility problems.