Comparison of the effects of 17 alpha-methyltestosterone, methandrostenolone, and nandrolone decanoate on the sexual behavior of castrated male rats.

In a series of 3 experiments, adult male Long-Evans rats were castrated and treated with 1 of 3 different anabolic-androgenic steroid (AAS) compounds (17 alpha-methyltestosterone, methandrostenolone, or nandrolone decanoate) for 6 weeks. In each experiment, subjects received daily injections of a high, medium, or low dose of AAS or the oil vehicle. The AAS effects on body weight in gonadectomized male rats were modest, and no effects on locomotor activity were observed. The AAS compounds administered at doses comparable with human abuse levels were not equipotent in maintaining male sexual behavior patterns (nandrolone decanoate > methandrostenolone > 17 alpha-methyltestosterone). In addition, the behavioral actions of AAS compounds did not parallel stimulation of sexual accessory glands. The authors reported that this study is the first to quantify the dose-response characteristics of individual AAS compounds with regard to these behavioral and endocrine measures.