Fluoxymesterone and the development of sexual behavior in the golden hamster.

Male hamsters castrated at birth and female hamsters were treated on postnatal Days 2-4 with 100 microgram of testosterone. 100 microgram of fluoxymesterone, or the hormone vehicle. As adults, mounting behavior and lordosis were measured following exogenous hormone treatment. Although the degree of penile or clitoral virilization did not appear to differ between testosterone- and fluoxymesterone-treated animals, behavioral differences occurred. Neonatal treatment with fluoxymesterone failed to "masculinize" or defeminize" behavior; neonatal testosterone treatment induced mounting in males and females and intromission in males. These results, along with those of others, indicate that fluoxymesterone has little or no central neural effect on sexual behavior in the hamster.