Kisspeptin reduces sexual dysfunction in a rat model of posttraumatic stress disorder

Abstract

BACKGROUND: Sexual dysfunction is not a specific symptom of posttraumatic stress disorder (PTSD); however, it is a common clinical complaint. Rodents exposed to a traumatic event exhibit behavioral disturbances in tests designed to measure emotional behavior. In relation to sexual behavior, exposure to acute stress leads to a decrease in the frequency of ejaculation and an increase in latency to first intercourse, first intromission, and ejaculation. Kisspeptin is a neuropeptide that plays important roles in the functioning of the hypothalamic–pituitary–gonadal axis and sexual behavior. AIM: To examine the effects of a single traumatic event caused by a predator on sexual behavior and motivation in male rats and correct them using hormonal and nonhormonal regulators. MATERIALS AND METHODS: We used 60 copulatory-naive male Wistar rats aged 90–100 days weighing 220–230 g, which were divided into six groups of 10 animals each. Animals of group 1 were intact; in the remaining groups, PTSD was modeled by exposure to a predator (tiger python). In the experimental groups, animals received buserelin, kisspeptin-10, and yohimbine. An unattainable reinforcement chamber was used to assess sexual motivation. The free locomotor activity of animals was evaluated in the “open-field” test. The elevated plus maze test was used to assess the effects of stress. Blood and brain samples were collected for testosterone and corticosterone enzyme-linked immunosorbent assay. RESULTS: Acute predator stress, as an animal model of PTSD, significantly reduces several components of sexual motivation in male rats and increases serum corticosterone levels. After chronic stress, both intranasal and systemic administrations of kisspeptin increase sexual motivation in male rats. Buserelin significantly affected testosterone secretion but had slightly affected sexual motivation. Systemic administration of kisspeptin partially restored testosterone production in a rat model of stress disorder. Yohimbine did not affect hormonal levels and had a disruptive effect on sexual motivation in rats. None of the hormonal and nonhormonal regulators used affected corticosterone levels. CONCLUSION:The findings indicate that exposure to predator stress has a greater effect on sexual motivation and the hypothalamic–pituitary–adrenal axis than on sex hormone production. This necessitates searching for new mechanisms underlying the regulation of reproductive behavior and the influence of stress factors on its implementation.