PRESENCE OF 11-BETA-HYDROXYSTEROID DEHYDROGENASE IN HUMAN SEMEN - EVIDENCE OF CORRELATION WITH SEMEN CHARACTERISTICS

11 beta-hydroxysteroid dehydrogenase (11 beta-HSD), the enzyme that ca talyzes the conversion of biologically active glucocorticoids to their inactive metabolites, was shown to be located exclusively in Leydig c ells of the rat testis, and its appearance was associated with the dev elopmental rise in testosterone. Thus, 11 beta-HSD was suggested to pl ay an important role in maintaining steroidogenesis by inactivating ex cess cortisol that inhibits testosterone production. Whether equivalen t protection from glucocorticoids excess is necessary for spermatogene sis is not known, and we have, accordingly, investigated the 11 beta-H SD activity in ejaculated human semen. Both 11 beta-dehydrogenase (11 beta-DH) and 11 beta-oxoreductase (11-OR) activities of 11 beta-HSD we re measurable in semen, although seminal plasma was devoid of 11 beta- HSD activity. Azoospermic specimens were associated with low 11 beta-d ehydrogenase activity, indicating the presence of enzyme activity in c ells other than spermatozoa. Pure spermatozoa separated on percoll gra dient could oxidize corticosterone in the presence of NAD or NADP. Sig nificantly higher 11 beta-DH activity is associated with semen specime ns with low sperm count (p < .05) and higher level of morphologically abnormal spermatozoa (p < .05). The presence of 11 beta-HSD in human s emen and its association with sperm characteristics thus suggests func tional role for glucocorticoid exclusion in the sperm maturation proce ss. (C) 1997 by Elsevier Science Inc.