Steroid metabolism by germ cells and spermatozoa in men after vasoepididymostomy.

The ability of germ cells (spermatocytes and spermatids) and spermatozoa present in human ejaculate to metabolize steroids was studied in men with obstructive infertility who had undergone vasoepididymostomy as corrective surgery. Steroid metabolism by spermatozoa in men who had undergone vasovasostomy was also investigated. Germ cells converted testosterone mainly to androstenedione. In addition to androstenedione, dihydrotestosterone and androstanediols were also formed in incubations using spermatids. Both types of germ cells converted estradiol to estrone. Spermatozoa from subjects who had undergone vasoepididymostomy or vasovasostomy converted testosterone to androstenedione as in normal men, while spermatozoa from infertile subjects converted testosterone mainly to dihydrotestosterone. Seminal fluid, free of germ cells, did not show steroid-metabolizing capability.