title: Impaired in vitro testicular endocrine function in elderly men.
abstract: Measurements of testosterone concentrations in peripheral and spermatic venous blood have yielded conflicting results concerning testosterone production in elderly men. To further elucidate the testicular endocrine capacity during aging, peripheral serum hormone levels and the in vitro conversion of progesterone and pregnenolone in histopathologically normal testicular tissue have been investigated in 22 elderly men and 28 younger adult males. The conversion mediated by 3 beta-hydroxysteroid-dehydrogenase and 17 alpha-hydroxylase was significantly higher (p less than 0.05 and p less than 0.01 respectively) in testicular tissue from the younger adult men, than in testicular tissue from elderly men. Since serum LH levels were significantly higher (p less than 0.01) and serum testosterone levels were significantly lower (p less than 0.01) in the elderly men, these data indicate that there was a primary endocrine impairment at the testicular level in the elderly men.
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D066298:In Vitro Techniques; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008875:Middle Aged; D011284:Pregnenolone / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism; D013254:Steroid 17-alpha-Hydroxylase / Q000378:metabolism; D013737:Testis / Q000201:enzymology / Q000502:physiology*; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone; D011374:Progesterone; D011284:Pregnenolone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D015096:3-Hydroxysteroid Dehydrogenases; D013254:Steroid 17-alpha-Hydroxylase