Experimental models for the investigation of female sexual function and dysfunction

There have been limited anatomic and physiological investigations of the fe male sexual arousal response. A broader understanding of the physiologic me chanisms of female sexual arousal function is required to improve the manag ement of women with sexual dysfunction, Three experimental test systems hav e been developed to understand better the biochemical and physiological mec hanisms of female sexual arousal response, An in vivo animal model was deve loped to record physiological and hemodynamic changes in the clitoris and v agina following pelvic nerve stimulation and administration of vasoactive a gents and physiological modulators. In vitro organ baths of clitoral and va ginal tissue were utilized to investigate mechanisms involved in the regula tion of smooth muscle contractility. In addition, primary cell cultures of human and animal clitoral and vaginal smooth muscle cells were developed to investigate signal transduction pathways modulating smooth muscle tone, In vivo studies revealed hemodynamic changes in vagina and clitoris in respon se to pelvic nerve stimulation, vasodilators and physiological modulators. Organ bath studies have demonstrated that clitoral and vaginal smooth muscl e tone is affected by non-adrenergic and non-cholinergic neurotransmitters, and the presence of functional alpha 1 and alpha 2 adrenergic receptors in these tissues has been established through biochemical studies. These chan ges are regulated by the tone of vascular and non-vascular smooth muscle in the vagina and clitoris. Primary cell culture studies have suggested that several physiological modulators such as vasoactive intestinal polypeptide (VIP), nitric oxide (NO), and prostaglandin E (PGE) regulate vaginal smooth muscle contractility. Data from experimental models have provided a prelim inary understanding of the mechanisms of the female sexual arousal response .