[Androgen binding proteins in human prostate (author's transl)].

Two high affinity saturable binding components were observed in the cytosol of hyperplastic human prostate gland using glyceroltris graident centrifugations having a sedimentation coefficient of 8-10 S and 4-5 S. Binding experiments with different steroids indicate that they correspond to the androgen-receptor protein on one hand and to sex steroid binding plasma protein (SBP) on the other hand. The calculated cytosol receptor concentration was 50 fentomoles/mg protein or 5,000 wites per cell. The SBP concentration, measured by equilibrium dialysis, indicated 8,000 sites per cell which represent 5% of the SBP concentration in the corresponding plasma. Prostate samples were submitted to constant flow organ culture in the presence of 3H-testosterone and increasing amounts of human serum albumin (HSA) and/or SBP. The uptake and metabolism of testosterone were measured and the results suggest that the SBP-testosterone complex could be associated with the prostate cells.