Seminal fluid androgen binding protein.

The following study was undertaken to determine the presence of an androgen binding protein (ABP) in the ejaculate. Seminal fluid was obtained from ten fertile subjects. Sperm counts ranged from 20 x 106/cc to 80 x 106/cc. Each sample was preincubated with tritiated dihydrotestosterone (DHT) and examined by polyacrylamide gel electrophoresis (PAGE). Second, after preincubation of the samples with tritiated DHT, the samples were mixed with Concanavalin-A bound to sepharose-D (C-S) and the supernate separated and counted. Finally, saturation analysis of the samples using dextran-coated charcoal for separation and counted. Finally, saturation analysis of the samples using dextran-coated charcoal for separation was performed and Scatchard analysis was used to determine the concentration of ABP present. PAGE demonstrated ABP in seven of ten samples studied. The bound counts of DHT were removed by C-S. The concentrations of ABP ranged from 0.132 to 0.468 nanomoles ABP/dl semen. These data indicate there is an ABP in seminal fluid similar to that from the Sertoli cell.