Sexual dimorphism of stress-induced changes in renal peripheral benzodiazepine receptors in rat

Adult male and female rats were exposed to either inescapable shock or no treatment. In vitro [ 3H]Ro 5-4864 (4′-chlorodiazepam) binding (1 nM) to peripheral benzodiazepine receptors (PRB) in both CNS and peripheral tissues indicated no gender differences in olfactory bulb, heart, lung or adrenal gland but a significant effect was observed in renal tissue. Female rats showed an attenuated stress-induced reduction (23%) in PBR in comparison to males (55%). This difference was shown to be an alteration of Bmax and not kD by Scatchard analysis. These data are the first demonstration of a sexual dimorphism in environmentally-induced alterations in PBR.