Exposure to an anabolic steroid changes female mice's sexual responses according to sex partner.

INTRODUCTION

Anabolic androgenic steroids (AAS) affect human female sexual behaviors. Animal models have been useful in uncovering the neural mechanisms governing changes in female sexual response upon AAS exposure.

AIM

We quantify the sexual response of AAS-exposed gonadally intact female mice when paired with gonadally intact female or male pairs.

METHODS

C57Bl/6 female mice were systemically exposed to the AAS 17alpha-methyltestosterone (7.5 mg/kg) for 17 days via a subcutaneous osmotic implant. On days 15-17, these females were allowed to mate with males or proestrus female partners in familiar and unfamiliar testing arenas for 10 minutes.

MAIN OUTCOME MEASURES

The following behavioral responses were registered: parameters related to mounting behavior such as the frequency of mounts, attempts to mount, and the latency to the first mount, anogenital investigation, fights and escapes, rejections, pelvic thrusts, and lordotic responses.

RESULTS

We found that males displayed a significant decrease in the frequency of mounts to AAS-exposed females, when compared with mating encounters with control females. We found no difference in the lordosis strength when control females were mounted by either a male or AAS-exposed females. However, females under androgen exposure attempted to mount control females, but not males, and their behavior was accompanied by significant increases in the number of fights, escapes, and rejections to the male. There were no differences between AAS-exposed females and males when the frequency of mounts and pelvic thrusts toward control females were compared. The lordotic quotient of control females was similar for either partner.

CONCLUSIONS

Aside from showing a male-like pattern, AAS-exposed females displayed a higher frequency of anogenital investigations toward control females than males, and their latency to the first mount was as fast as that of males. Taken together, we conclude that the sex partner greatly influences the sexual response of AAS-exposed female mice.