Adrenal secretion and plasma CBG levels in the immature male rat: Effects of 5α reduced androgens and antiandrogens

Abstract

The present study describes the effects of the 5α reduced androgens dihydrotestosterone propionate (DHTP)and 5a androstan-3α,17β-diol (ADIOL), and the anti-androgens cyproterone (CYP) and cyproterone acetate (CA) on plasma glucocorticoids and corticosterone binding globulin (CBG) in the immature male rat. Both DHTP and ADIOL had dose-dependent inhibitory effects on the blood levels of corticosterone and CBG. However, DHTP inhibited plasma corticosterone levels relatively more than CBG, whereas ADIOL reduced both corticosterone and CBG to approximately the same extent; in both cases plasma corticosterone was reduced to a level which was approximately 40% of the control level. Cyproterone and CA reduced plasma corticosterone levels to a greater degree than was observed with DHTP or ADIOL. On the other hand, plasma CBG levels were either unaffected or only marginally decreased by anti-androgen treatment. The conclusions made from this study were: (a) 5α reduced androgens have inhibitory effects on the pituitary-adrenal axis of the intact immature male rat. (b) the inhibitory effects of ADIOL on corticosterone levels can mainly be explained by its effects on CBG whereas DHTP appears to have an additional effect on adrenal secretion, (c) both anti-androgens exert a pronounced inhibitory influence on corticosterone levels via a mechanism which does not involve CBG.