Early effects of hCG on human testicular cyclic AMP content, protein kinase activity, in-vitro progesterone conversion and the serum concentrations of testosterone and oestradiol.
Ten infertile men underwent testicular biopsy. Cyclic AMP concentration and cAMP-dependent protein kinase activity were determined in biopsies obtained before, and at 3, 10, 20 and 30 min after an intravenous injection of hCG (1500-5000 IU). The in-vitro conversion of progesterone by testicular tissue, and the serum concentrations of testosterone and oestradiol were then studied before and at 30 min after hCG injection. Intravenous injection of hCG induced a rapid increase in cAMP concentration and in the activity of cAMP-dependent protein kinase. The kinetics of this response indicated that cAMP and cAMP-dependent protein kinase mediate hCG effects on the human testis, presumably via effects on the Leydig cells. No stimulatory effect on steroid conversion in vitro or on the serum concentrations of testosterone and oestradiol were seen after 30 min.
Petersson
F
F
Department of Obstetrics and Gynaecology, University Hospital of Linköping, Sweden.
Andersson
R G
RG
A:son Berg
A
A
Hammar
M
M
D000328:Adult; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D000242:Cyclic AMP / Q000032:analysis*; D004958:Estradiol / Q000097:blood; D006801:Humans; D007248:Infertility, Male / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D011374:Progesterone / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism*; D013737:Testis / Q000032:analysis / Q000187:drug effects* / Q000201:enzymology; D013739:Testosterone / Q000097:blood; D013997:Time Factors
D006063:Chorionic Gonadotropin; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D000242:Cyclic AMP; D011494:Protein Kinases