PERINATAL FLUTAMIDE AND MOUNTING AND LORDOSIS BEHAVIOR IN ADULT FEMALE WISTAR AND SPRAGUE-DAWLEY RATS

The present study was designed to investigate the possible role of perinatal androgens acting via the androgen receptor, as opposed to the estrogen receptor, for the differentiation of adult mounting and lordosis behavior in female rats. Female Wistar (W) and Sprague-Dawley (SD) rats were exposed to the anti-androgen flutamide prenatally (days 11-22 of pregnancy) and/or neonatally (days 1-10). The females were ovariectomized in adulthood and repeatedly tested for mounting and lordosis behavior. Flutamide, given both pre- and neonatally to SD rats, reduced adult T-induced female mounting. Flutamide administered only prenatally or only neonatally did not lower adult mounting behavior of SD rats. Mounting behavior of female W rats, following pre- and/or neonatal flutamide treatment was not affected. Lordosis behavior was also not altered by perinatal flutamide treatment of either strain. The results of the present study, no effect of prenatal flutamide, do not support the hypothesis that female rats require prenatal androgen receptor-mediated actions of testosterone in the organization of neural tissues for the occurrence of adult mounting and lordosis behavior. Only in SD rats androgenic organization of adult mounting behavior via the androgen receptor seems to occur both pre- and neonatally. Since clear behavioral effects of prenatal flutamide treatment have been published earlier in Long-Evans females, we suggest strain differences in sensitivity for perinatal androgenization in female rats. Future research into that possibility is needed.