Effects of prolonged exposure to anabolic steroids on the behavior of male and female mice.

Adult male and female mice were exposed to a combination of four anabolic-androgenic steroids at pharmacological doses for 6 months. Males were exposed to either 5 or 20 times androgenic maintenance levels, as determined by bioassay; females were exposed to either one or five times the maintenance levels for males. Even the low doses were sufficient to reduce gonadal weight in both sexes and eliminate the estrous cycle in females. Steroid treatment blocked ejaculation in most males without influencing other facets of their sexual behavior. In some females steroid treatment elicited male-like mounting and pelvic thrusting. Exposure to steroids increased aggressiveness in females. Using a different testing protocol, steroid exposure had no effect on aggressiveness in males. Steroid treatment decreased the use of a running wheel significantly in females and marginally in males. Overall, the results of this experiment suggest no enhancement of normal androgen-mediated behavior in males, but potent effects on the behavior of females.