Physiology of Female Sexual Function: Animal Models

Abstract

Introduction Data concerning the physiology of desire, arousal, and orgasm in women are limited because of ethical constraints. Aim To gain knowledge of physiology of female sexual function through animal models. Methods To provide state-of-the-art knowledge concerning female sexual function in animal models, representing the opinions of seven experts from five countries developed in a consensus process over a 2-year period. Main Outcome Measure Expert opinion was based on the grading of evidence-based medical literature, widespread internal committee discussion, public presentation, and debate. Results Sexual desire may be considered as the presence of desire for, and fantasy about, sexual activity. Desire in animals can be inferred from certain appetitive behaviors that occur during copulation and from certain unconditioned copulatory measures. Proceptive behaviors are dependent in part on estrogen, progesterone, and drugs that bind to D1 dopamine receptors, adrenergic receptors, oxytocin receptors, opioid receptors, or gamma-amino butyric acid receptors. Peripheral arousal states are dependent on regulation of genital smooth muscle tone. Multiple neurotransmitters/mediators are involved including adrenergic, and nonadrenergic, noncholinergic agents such as vasoactive intestinal polypeptide, nitric oxide, neuropeptide Y, calcitonin gene-related peptide, and substance P. Sex steroid hormones, estrogens and androgens, are critical for structure and function of genital tissues including modulation of genital blood flow, lubrication, neurotransmitter function, smooth muscle contractility, mucification, and sex steroid receptor expression in genital tissues. Orgasm may be investigated by urethrogenital (UG) reflex, in which genital stimulation results in rhythmic contractions of striated perineal muscles and contractions of vagina, anus, and uterine smooth muscle. The UG reflex is generated by a multisegmental spinal pattern generator involving the coordination of sympathetic, parasympathetic, and somatic efferents innervating the genital organs. Serotonin and dopamine may modulate UG reflex activity. Conclusion More research is needed in animal models in the physiology of female sexual function.

Testosterone and Erectile Function: From Basic Research to a New Clinical Paradigm for Managing Men with Androgen Insufficiency and Erectile Dysfunction

“…Dopamine agonists-Dopamine agonists have been reported to improve sexual function [159] on the basis of research showing that sexual motivation is modulated by a number of central nervous system neurotransmitter and receptor changes induced, in part, by the action of sex steroids and by the central neurotransmitter dopamine. Dopamine neurotransmitter systems may play a critical intermediary role in the central regulation of sexual arousal and excitation, mood, and incentive-related sexual behavior, particularly in the motivational responses to conditioned external stimuli [160][161][162][163][164]. Although their use is controversial, more research is needed with dopamine agonists for men with androgen insufficiency and ED.…”

Sexual and reproductive abnormalities in patients with spinal cord injuries

“…Paralimbik alan ve erkekte olduğu gibi hipotalamik nükleuslar kadınlarda da santral cinsel uyarı merkezleridir. [14,15] Buradan kalkan uyarılar omuriliğin torakospinal (T10-L2) ve sakrospinal (S2-4) segmentlerinden çıkarak genitallerde fizyolojik değişiklikler oluşturur. [15] Genitallerden kalkan uyarılar da beyinde cinsel isteği ve uyarıyı daha da artırır.…”

“…[14,15] Buradan kalkan uyarılar omuriliğin torakospinal (T10-L2) ve sakrospinal (S2-4) segmentlerinden çıkarak genitallerde fizyolojik değişiklikler oluşturur. [15] Genitallerden kalkan uyarılar da beyinde cinsel isteği ve uyarıyı daha da artırır. Kadınlarda cinsel uyarılma sırasında klitoriste tümesans (klitoris tunika albugineası ince ve tek kat olduğu için rijid ereksiyon gerçekleşemez), labia minorada 2-3 kat çap artışı, vajende genişleme ve uzama ile eksudasyon (lubrikasyon) olur.…”

Central nervous system-acting agents and the treatment of erectile and sexual dysfunction

“…The paraventricular nucleus (PVN) of the hypothalamus seems responsible for increased sexual function [5,6]. Tracks from the penis, as well as ischiocavernosus and bulbospongiosus muscles, have been identified in the PVN using a pseudorabies retrograde injection model of the corpora cavernosa [1••,2].…”