Effects of chronic sulpiride-induced hyperprolactinemia on plasma testosterone and its responses to hCG in normal men.
To elucidate the effects of sulpiride-induced (300 mg daily) long-term (64 days) hyperprolactinemia on basal and hCG-stimulated plasma testosterone (T), hCG was given to five normal men five times at 2-week intervals (before sulpiride administration and at 2, 4, 6 and 8 weeks). Mean integrated hCG responses of plasma T did not change significantly as compared with baseline. However, mean (+/- SEM) basal plasma levels of T decreased significantly (P less than 0.05) from 1011 +/- 148 ng/dl to 852 +/- 13 at 2 weeks, 520 +/- 53 at 4 weeks, 572 +/- 137 at 6 weeks and 554 +/- 140 at 8 weeks. These results suggest that sulpiride-induced hyperprolactinemia (73.8 ng/ml, the average of mean values obtained at 2, 4, 6 and 8 weeks) for 64 days does not suppress secretion of T in response to hCG in spite of a decrease in basal plasma T concentrations. It is unlikely that the low concentrations of plasma T are due to direct effects of hyperprolactinemia on the testis.
Oseko
F
F
Department of Internal Medicine, Shimane Medical University, Japan.
Oka
N
N
Furuya
H
H
Morikawa
K
K
D000328:Adult; D000368:Aged; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D006801:Humans; D006966:Hyperprolactinemia / Q000139:chemically induced*; D007989:Libido / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D013469:Sulpiride; D013737:Testis / Q000187:drug effects; D013739:Testosterone / Q000097:blood*
D006063:Chorionic Gonadotropin; D013739:Testosterone; D013469:Sulpiride