Effects of anabolic steroids on hormone-binding proteins, serum cortisol and serum nonprotein-bound cortisol.

Abstract

The effects on plasma proteins of the anabolic steroids oxymetholone, methandrostenolone, stanozolol, fluoxymesterone, oxandrolone, norethandrolone, ethylestrenol, nandrolone phenpropionate and methandriol dipropionate, as well as 17α-methyltestosterone, given orally and sublingually, testosterone propionate sublingual and parenteral aqueous testosterone, were studied on both volunteers and patients. The responses of thyroxine-binding globulin (TBG), thyroxine-binding prealbumin (TBPA), cortisol-binding globulin (CBG), serum cortisol and nonprotein-bound cortisol (NPC) were studied. The 17α-alkylated anabolic steroids induced marked changes, with significant elevations of TBPA and depression of TBG; CBG was significantly increased by oxymetholone and methandrostenolone. Both the latter steroids have conjugated and unsaturated resonating systems in ring A. On the other hand, the non-17α-alkylated androgens did not produce these changes. The C-3 ketone group, absent from ethylestrenol, seemed also to be important for effects upon these plasma protein concentrations. These effects on plasma proteins are dose related and different from the ones obtained with estrogens or during an acute phase reaction. Only methandrostenolone produced a significant increment in cortisol, and none of the anabolic steroids significantly changed NPC. A negative correlation (r= −0.78; p<0.01) was found between the ability to produce nitrogen retention in man and the degree of depression of TBG serum levels, for different anabolic steroids. It is concluded that in general a 17α-alkyl group, and to a lesser degree a C-3 ketone group, are necessary for those changes in plasma proteins. Additional unsaturation in ring A (other than the α, β unsaturation) may result in changes in CBG and is consistent with the effect of estrogen on this protein.