An environmental antiandrogen, vinclozolin, alters the organization of play behavior

During mammalian sexual differentiation, the androgens, testosterone and dihydrotestosterone are critical for the organization of the male phenotype. In rats, play behavior is sexually dimorphic. Administration of exogenous androgens during the perinatal period results in masculine-like play behavior of juveniles. Recently, there has been increasing concern about the potential for environmental endocrine-disrupting chemicals (EDCs) to alter sexual differentiation in mammals. One such EDC is the fungicide and androgen receptor (AR) antagonist, vinclozolin. We tested whether developmental exposure to an EDC could alter androgen-dependent behaviors such as play. To examine this possibility, neonatal male rats were injected from Postnatal Days (PND) 2 to 3 with corn oil, pharmacological antiandrogen flutamide (50 mg/kg/day) or vinclozolin (200 mg/kg/day); whereas neonatal females were treated either with corn oil or testosterone propionate (TP, 250 microg/kg/day). At PNDs 36-37, animals were observed for social play. Behaviors associated with general social activity, such as sniffing and dorsal contact, were unaffected by treatment or sex. However, play behavior in males treated with flutamide or vinclozolin was significantly reduced to near-female levels when compared to control males. Play behavior in females exposed to TP during the neonatal period was significantly increased when compared with control females. Hence, this study suggests that perinatal exposure to vinclozolin, an environmental antiandrogen, can alter androgen-dependent behavior, such as play, in the male rat.