Effect of the 5-HT receptor agonist DOI on female rat sexual behavior

Female rats display a repertoire of behaviors during a sexual encounter with a male, including sexually receptive (the lordosis response) and proceptive (darts and hops, and ear wigglings) behaviors.

We investigated the effects of subcutaneous injection of the 5-HT(2A/2C) receptor agonist (2,5-dimethoxy-4-idophenyl)-2-aminopropane hydrochloride (DOI) on sexual behaviors of ovariectomized female rat hormonally supplemented with estradiol benzoate (10 microg) and progesterone (250 microg).

Both female and male sexual behaviors were observed for 10 minutes (pretest). Then females were injected with the treatment and after a 10-minute delay replaced with the same male for a 30-minute mating test (posttreatment period).

DOI (0.5 and 1 mg/kg) significantly increased the number of darts and hops/mounts. In contrast, no significant differences in ear wigglings/mounts were observed. In addition, DOI failed to modify sexual receptivity.

These data suggest that 5-HT(2A/2C) receptors are important in the regulation of female proceptivity.