In vitro conversion of progesterone in the human testis at different ages, pathophysiological conditions, and during treatment with estrogens or gonadotrophic hormones.
The enzyme 17 alpha-hydroxylase catalyzes the conversion of progesterone to 17 alpha-hydroxyprogesterone in the testis and may be studied with the use of incubation of testicular tissue with [3H] progesterone in vitro. The enzyme 20 alpha-hydroxysteroid dehydrogenase catalyzes the conversion of progesterone to 20 alpha-dihydroprogesterone. These enzymes were studied in testicular tissue from 105 human males regarding the effects of aging, different pathophysiological conditions, and gonadotrophic or estrogenic treatment. 17 alpha-Hydroxylase activity was low in vitro in testicular tissue from prepubertal boys, adult men with pituitary tumors, and estrogen-treated elderly men. In nontreated elderly men and certain infertile adult men, 17 alpha-hydroxylase was more active than in the above-mentioned patient groups, albeit lower than in adolescent and adult men. Gonadotropic treatment increased the conversion mediated by 17 alpha-hydroxylase in prepubertal as well as adult testicular tissue. In conclusion, the activity of 17 alpha-hydroxylase may be influenced by gonadotrophic hormones and may be an indicator of the testicular endocrine state at the moment of biopsy. Testicular 20 alpha-hydroxysteroid dehydrogenase seems to be active during low gonadotrophic influence and might even be inhibited by gonadotrophic stimulation.
Hammar
M
M
Petersson
F
F
Berg
A A
AA
D015089:20-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000375:Aging; D002648:Child; D002675:Child, Preschool; D006063:Chorionic Gonadotropin / Q000627:therapeutic use*; D003456:Cryptorchidism / Q000201:enzymology; D004967:Estrogens / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007248:Infertility, Male / Q000201:enzymology; D008297:Male; D008596:Menotropins / Q000627:therapeutic use*; D010911:Pituitary Neoplasms / Q000201:enzymology; D011247:Pregnancy; D011374:Progesterone / Q000378:metabolism*; D011627:Puberty; D013254:Steroid 17-alpha-Hydroxylase / Q000378:metabolism; D013737:Testis / Q000187:drug effects / Q000196:embryology / Q000201:enzymology*
D006063:Chorionic Gonadotropin; D004967:Estrogens; D011374:Progesterone; D008596:Menotropins; D015089:20-Hydroxysteroid Dehydrogenases; D013254:Steroid 17-alpha-Hydroxylase