Suggestion of abnormal testicular steroidogenesis in some oligospermic men.

Androgen biosynthesis in the testis may be analyzed in some detail by means of techniques of in vitro incubation of small testicular biopsy specimens with suitable radiolabelled precursors. Sixty-six tissue specimens from 33 patients who underwent bilateral testicular biopsies because of infertility were incubated in vitro with [3H]pregnenolone in order to investigate the possibility of abnormalities in their steroid biosynthetic activity. As a normal control, testicular tissue obtained by testicular biopsy from a young normal volunteer was used. The distribution of metabolites in the incubates of testes from 8 infertile men differed greatly from the remaining 25 patients and the normal control. The major steroids formed from pregnenolone by the testes of those 8 men were 17-hydroxypregnenolone, dehydroepiandrosterone, 20alpha-dihydropregnenolone and and 20alpha-dihydro-17-hydroxypregnenolone. Very small amounts of delta4-3 oxo products (progesterone, 17-hydroxyprogesterone, androstenedione and testosterone) were formed suggesting a deficiency of 3beta-hydroxy-steroid-dehydrogenase activity in the testes of these 8 men, possibly related to the derangement of their spermatogenic function.