Kisspeptin is Testosterone independent regulator of Sexual Motivation in Male Rats

Abstract

Kisspeptin is the peptide product of the KISS-1 gene and endogenous agonist for the Kiss1 receptor. It is well known that kisspeptin acts centrally, and stimulates the secretion of gonadoliberin (GnRH). Further, Kisspeptin also interacts with other neuropeptides such as neurokinin B and dynorphin to regulate GnRH pulse generation and plays a key role in sexual behavior. This study aimed to evaluate the effect of kisspeptin on male rats' sexual motivation and its dependence on testosterone levels. In this study total of 50 copulation naive male Wistar rats were collected and divided into 5 groups (10 rats in each group), among these first group received only saline (control), the second group has been given 20μg buserelin acetate (GnRH analogue), the third group has been given intranasally kisspeptin-10 (3ng), the fourth has been received intraperitoneally kisspeptin-10 (30ng) and the fifth group has been given Yoquimbine 200 µg. Behavioral effects were registered in the open-field reward-proximity chamber with a female in the estrous phase of the cycle over the transparent perforated wall for 10 minutes in red light. Blood samples were collected from the tail vein after 30 minutes of the substance administration and in the collected blood samples, testosterone concentration was measured by the ELISA method. All animal groups were compared with each other by the ANOVA test and correspondent “post hoc” paired tests of Newman–Kruskall– Wallis test and Dunn’s test. Intranasal administration of buserelin acetate increased the concentration of testosterone but did not affect sexual motivation in rats. Further, intraperitoneal administration of Kisspeptin-10 enhances testosterone concentration and sexual motivation. While intranasal administration of kisspeptin-10 didn’t enhance testosterone level but increased sexual motivation. Results of this study showed some effects of kisspeptin along with the independent regulation of steroids.