Suppressive effects of dehydroepiandrosterone and 3-beta-methylandrost-5-en-17-one on attack towards lactating female intruders by castrated male mice.

Three experiments were performed. In Experiment I, triads of adult castrated male mice were chronically administered with either oil-vehicle or 80 micrograms/day of dehydroepiandrosterone (D) or 3-beta-methylandrost-5-en-17-one (D-CH3). They were subsequently tested for their attack on a lactating intruder female introduced for 15 min in their home-cage, 2 hr after their last injection. Both D and D-CH3 significantly reduced male aggressive responses (cf. oil-injected category). In Experiment II the effects of D-CH3 dosed at 20, 40 or 80 micrograms/day were measured in the same testing situation. D-CH3 dose-dependently reduced the mice attack probability on lactating intruders with the highest dose being the most effective. Finally, to test in Experiment III that D-CH3 was not demonstrably androgenic, castrated males received daily injections of 20, 40 or 80 micrograms of this synthetic steroid for 4, 8, 16 or 32 days before tissue sampling. At all doses and whatever treatment duration, D-CH3 did not significantly increase the weights of the accessory sex organs.