Androgen-binding components of human semen

Androgen-binding components were detected in human semen, using the dextran-coated charcoal method. Pre- and postvasectomy semen samples did not show significant differences in ability to bind dihydrotestosterone. Electrophoresis conducted in polyacrylamide gels in which tritiated dihydrotestosterone had been incorporated disclosed the presence of androgen-binding protein with properties characteristic of the ABP of Sertoli cell origin in ram semen but ABP was not detectable in human semen, even after concentrating it two or four fold. The binding of dihydrotestosterone was slightly greater in the later portion of split-ejaculate samples, but binding was found in the earlier fraction and in prostatic fluid, suggesting that androgen-binding components enter human semen with secretions of the prostate and seminal vesicle glands. It was concluded that the extent of androgen-binding by human seminal fluid is not a measure of Sertoli-cell function.