Presence of binding component(s) for testosterone in rat liver cytosol.

Abstract

The existence of testosterone-binding component in the cytosol fraction of the male rat liver was shown. The binding ability of the component with testosterone was decreased by the addition of excess unlabeled steroids [androstenedione; 5.alpha.-dihydrotestosterone; androsterone; 5.alpha.-androstane-3.alpha.,17.beta.-diol; 5.beta.-androstane-3.alpha.,17.beta.-diol; estradiol-17.beta. and cortisol], but the steroid binding activity of the serum was not affected. The Scatchard plot indicated that the component has a moderate binding affinity with testosterone and the number of the binding sites of the component is limited.