CELL-KINETICS OF THE RAT SEMINIFEROUS EPITHELIUM FOLLOWING LEAD ACETATE TREATMENT

The present studies are related to the effects of oral administration of lead acetate on rat spermatogenesis. In addition to the observation s of greatly inhibited sperm motility and a reduced sperm count in the lead acetate-fed rats, as obtained in our earlier studies [Leblond et al.: Physiol Rev 52:198-236, 1972], it was considered important to st udy the cell kinetics in the seminiferous epithelium, a site for the g eneration of sperm. Lead-induced shrinkage of the seminiferous tubules was observed with a significant decrease in tubular diameter and germ inal height. An overall decrease in all cell types was seen with maxim um lead acetate effects on the fully mature spermatids. A ratio betwee n the number of cells at various sequential stages was also determined . The ratios of the young spermatids to the pachytene spermatocytes an d the mature spermatids to young spermatids were significantly low in the different lead-treated groups. Some depression of spermatogenesis at the young spermatid stage was observed at higher lead acetate doses . However, the arrest of spermatid maturation at the lowest dose of le ad was complete. The maximum toxicity at the lowest dose of lead proba bly relates to the bioavailability of lead, which may be checked by th e induction of lead-binding proteins as the higher lead levels. (C) 19 96 Wiley-Liss, Inc.