Pre- and neonatal exposure to cimetidine but not ranitidine adversely affects adult sexual functioning of male rats.

Cimetidine, ranitidine or water were administered to pregnant rats from the 12th day of pregnancy through weaning at 21 days of age. The effects of such treatments upon the male progeny were evaluated. Anogenital distance and indices, measures of masculinity, were found to be reduced (p less than 0.05) in pups of cimetidine-exposed dams but not in the pups obtained from either the ranitidine or water controls. In addition, at 55 days and 110 days of age, the testes and ventral prostate-seminal vesicles (androgen responsive tissues) of the rats exposed to cimetidine were smaller (p less than 0.05) than those of the other two groups. Moreover, at both 55 and 110 days of age, the testosterone levels were reduced (p less than 0.05) in these same pups. Despite the fact that the cimetidine-exposed animals had reduced testosterone levels compared to the other two groups, the LH levels did not differ between the three groups. Finally, both before and after exogenous androgen replacement, the sexual behavior of the cimetidine exposed animals was diminished when compared to that of the other two groups. These results suggest that cimetidine but not ranitidine adversely affects male androgenization and neuroendocrine programming and suggests that its use in pregnant women may adversely affect the adult sexual behavior and development of their male progeny.