Effect of opoid antagonists on hormonal modulation and their relation to male reproduction

ABSTRACT

Twenty-four adult male Sprague Dawley rats were used to study the effect of acute administration of naloxone [4 mg/kg b. wt.] on FSH, LH and prolactin levels and its relation to male sexual functions on both intact [n= 12] and castrated male rats [n= 12]. In case of the intact male rats FSH and LH levels were increased significantly [P <0.01] in the treated group. However, prolactin level was decreased significantly [P <0.01]. Also, the viability and motility percentages of the epididymal sperm were decreased significantly in treated group. Minimal degenerative changes were observed in treated group. No significant changes were observed in exploratory and sexual behavior parameters in both groups. In sexually inactive rats [chronically castrated 2 weeks before experiment then treated with 2.5 mg/kg b. wt. testosterone propinate], both FSH and LH levels were increased significantly [P <0.01] in treated group. However, the prolactin level was decreased significantly [P <0.01]. The exploratory and sexual behavior parameters were not changed