Diminished luteinizing hormone release in prenatally stressed male rats after exposure to sexually receptive females.

Prenatally stressed (P-S) males show reductions in male sexual behavior, medial preoptic area volume, and levels of circulating testosterone. We examined the luteinizing hormone (LH) response to the presence of a sexually receptive female, a known index of sexual arousal. Adult male offspring from mothers stressed on days 15-22 of pregnancy (thrice-daily exposures to heat, light, and restraint) were implanted with an intraatrial catheter. Forty-eight h later they were placed into test chambers divided by a wire mesh partition; the catheter was extended outside the chamber. Thirty min later a baseline blood sample (time 0 min) was taken and a sexually receptive female was then placed on the side of the partition opposite the male for 60 min. Blood samples were collected 5, 10, 15, 30, 60 min, and 24 h after introduction of the female. Prenatally stressed males exhibited significantly lower LH levels following exposure to the female at each time point, 5 min to 24 h. Furthermore, at no point were P-S males' LH levels significantly increased above baseline levels. These data suggest that attenuations in female-induced LH release are associated with the marked reductions in male sexual behavior characteristic of the P-S male.