Selective facilitation of sexual solicitation in the female rat by a melanocortin receptor agonist

Disorders of sexual desire affect an estimated 30% of women in North America and Europe, with etiologies based on interpersonal, personal, and physiological factors. There are currently no pharmacological agents approved for use in the treatment of female sexual dysfunction. This is due, in part, to a focus on the effects of experimental drugs on reflexive components of sexual behavior, such as lordosis, in animal models. Here we report that PT-141, a peptide analogue of alpha-melanocyte-stimulating hormone that binds to central melanocortin receptors, selectively stimulates solicitational behaviors in the female rat. This occurs without affecting lordosis, pacing, or other sexual behaviors. PT-141 did not cause generalized motor activation, nor did it affect the perception of sexual reward. A selective pharmacological effect on appetitive sexual behavior in female rats has not been reported previously, and indicates that central melanocortin systems are important in the regulation of female sexual desire. Accordingly, PT-141 may be the first identified pharmacological agent with the capability to treat female sexual desire disorders.