In rats, giving kisspeptin-10 through the nose boosted sexual interest without raising testosterone, while injecting it raised both testosterone and sexual interest. This shows kisspein can affect libido through a pathway that doesn’t rely on testosterone.

Kisspeptin is the peptide product of the KiSS-1 gene and endogenous agonist for the Kiss1 receptor. It is known that kisspeptin, acting centrally, stimulates secretion of gonadoliberin (GnRH). Kisspeptin interacts with other neuropeptides such as neurokinin B and dynorphin, to regulate GnRH pulse generation and also plays a role in sexual behaviour. In this study 50 copulation naive male Wistar rats divided into 5 groups received saline, buserelin acetate (GnRH analogue) (20 μg), kisspeptin-10 (3 ng) intranasally, kisspeptin-10 (30 ng) intraperitoneally and Yoquimbine 200 µg. Behavioural effects were registered in the open-field reward-proximity chamber with the female in estrous phase of cycle over the transparent perforated wall for 10 minutes in red light. Blood samples were collected 30 min after the substance administration from tail vein. Testosterone concentrations were measured using ELISA. All animal groups were compared one to another 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 concentration of testosterone but not affect sexual motivation in rats. Intraperitoneal administration of Kisspeptin-10 affect both of testosterone concentration and sexual motivation. Intranasal administration of kisspeptin-10 didn't act testosterone but increased sexual motivation. This study shows that some behavioral effects of kisspeptin can possibly be realized independently of testosterone concentration changes.