The Effect of Perinatal Blockade of Androgen Receptors on the Expression of Hypothalamic Estrogen Receptor-A and Sexual Motivation in Male Rats

The study investigated the effects of perinatal blockade of androgen receptors (AR) on the expression of hypothalamic estrogen receptor-a (ER-a) and sexual motivation in male Long Evans rats. Flutamide, an anti-androgen agent, was administered during the critical period of sexual dimorphism, and the rats were later treated with finasteride, letrozole, or a vehicle in adulthood. The results showed that Flutamide-treated rats exhibited no preference for gonadally-intact or ovariectomized females, and had significantly increased hypothalamic ER-a and serum estrogen levels. This suggested that blocking AR during the perinatal period led to a permanent increase in estrogen and ER-a expression in the hypothalamus, rendering further manipulations during the activation period ineffective.