[Androgen-protein interactions in the cytosol of the liver and prostate in aging]

The androgen-protein interactions in liver and ventral prostate cytosol of immature (1.5 months), young (6 months), mature (12 months) and old (24 months) male rats were studied. The minimum content and maximum values of association constant of testosterone-binding proteins in liver cytosol were observed in immature rats. Maximum concentration of testosterone-binding sites was in young and mature rats and decreased in old animals, thus correlating with synthesis of alpha 2u-globulin in ontogenesis. The binding affinity of testosterone-binding proteins in rats aged 6, 12 and 24 months were approximately equal. As for ventral prostate, the maximum content of 5 alpha-dihydrotestosterone-binding proteins was revealed in immature rats. In young mature rats the ventral prostate concentration of binding sites for 5 alpha-dihydrotestosterone decreased three-fold in comparison with the rats aged 1.5 months. Minimum content of 5 alpha-dihydrotestosterone-binding sites was found in the old rats. Binding affinity of 5 alpha-dihydrotestosterone-binding proteins was approximately the same in rats aged 1, 5, 6, and 12 months and increased in old animals. The age-dependent reduction of androgen-binding sites in rat ventral prostate cytosol was followed by a marked decrease in the weight of the ventral prostate.