The influences of androgen on sociosexual behavior: a comparison between the spontaneously hypertensive (SHR) and the Wistar-Kyoto rat (WKY)

Abstract

Differences in androgen-dependent forms of behavior and plasma testosterone levels in the spontaneously hypertensive rat (SHR) and its normotensive counterpart the Wistar-Kyoto rat (WKY) are described here. Copulatory behavior (solitary test to avoid influence of experience) and certain androgen-dependent elements of sociosexual orientation were significantly attenuated in the SHR compared to the WKY male rat. After castration, the differences in sociosexual orientation were no longer apparent. In contrast, differences in other behavioral elements, such as locomotion, were unchanged after castration. Plasma testosterone levels were significantly higher in the SHR than in the WKY male rats. Taken together, the behavioral and hormonal data suggest a decreased central nervous responsiveness to androgens in the SHR rats. This could lead to reduced androgen-dependent behavior, and possibly also to a decreased testosterone feedback control.