Behavioral and hormonal changes following the continuous administration of testosterone in females in capuchin monkey adult females (Sapajus Libidinosus)

Although the role of estradiol in female sexual behavior is well documented, some studies have suggested a joint action of this steroid with testosterone in modulating female sexual behavior. Therefore, the objective of this study was to evaluate the effects of testosterone administration on the behavioral and hormonal aspects of female capuchin monkeys (Sapajus libidinosus). 12 adult female capuchin monkeys kept at the Primatology Center of the University of Brasília were used. The study was divided into three phases, that is, 1st phase: baseline (24 days); 2nd phase: testosterone treatment (63 days) and 3rd phase: Placebo (63 days), totaling 150 consecutive days. The sexual and non-sexual behavior of the monkeys was monitored throughout the phases using the Focal Animal Method. For hormonal analyses, 15 blood samples were collected from each female every 10 days. An increase in the frequency of expression of sexual behavior (p<0.05) and serum levels of testosterone and DHT (p<0.05) was observed during testosterone treatment. Thus, this study points to a positive effect of exogenous testosterone in modulating the sexual behavior of female capuchin monkeys. The results of this study may contribute to a better understanding of continued testosterone use in humans and may be useful in assessing the risks of chronic testosterone use.