Effects of stress on female rat sexual function.

This study was undertaken to investigate whether prolonged stress interferes with sexual behavior and changes biochemical and physiologic mechanisms. Experiments were repeated three times with different rats in each period. In all, 63 female Sprague-Dawley rats were employed, with 21 rats in each period, and the control group was maintained at room temperature with free access to food and water. The stress group was maintained under a scheduled stress condition for 10 days, and seven rats from the group were randomly selected and exposed to the control environment for 10 days as the recovery group. Sexual behavior, hormonal values, and neuronal and endothelial nitric oxide synthase (nNOS and eNOS) expressions of vaginal tissue were analyzed and compared. Serum testosterone levels were significantly elevated in the stress and recovery groups (P<0.05). Female rats in the stress group showed reduced receptivity to their male mates (P<0.05). Western blot analysis demonstrated that nNOS and eNOS expressions were significantly lower in the stress group (P<0.05) than in the other groups. We conclude that chronic physical stress modifies the sexual behavior of female rats through a mechanism believed to involve complex changes in sex hormones, endocrine factors, and neurotransmitters.