Treatment with growth hormone suppresses cortisol production in man.
The effect of biosynthetic human growth hormone (GH) on the cortisol production rate was determined in healthy men (N=8) using the stable isotope dilution technique and mass spectrometry. 1alpha,2alpha-D-Cortisol was infused at a dose of 110+/-9 microg/h for 10 hours (8 AM to 6 PM). Blood samples obtained at 20-minute intervals from 2 PM to 6 PM were pooled during two 2-hour periods. Subsequently, each subject received a daily dose of biosynthetic human GH (4 IU/d subcutaneously [SC]) for 7 days. This resulted in an increase of plasma somatomedin C from a basal level of 0.65+/-0.13 U/mL to 1.18+/-1.2 U/mL on day 7 (P < .0001). Plasma concentrations of corticotropin (ACTH) and cortisol-binding globulin (CBG) were similar before and after administration of GH. Determination of the cortisol production rate was repeated on day 7 of treatment with GH. Due to its physiological diurnal rhythmicity, endogenous production of cortisol during basal conditions was higher (P < .05) between 2 and 4 PM (0.70+/-0.30 mg/h) versus 4 to 6 PM (0.55+/-0.28 mg/h). Following treatment with GH, the values were 0.40+/-0.11 mg/h (2 to 4 PM, P < .01 v day 1) and 0.31+/-0.11 mg/h (4 to 6 PM, P < .01 v day 1). Thus, in healthy men, treatment with SC, GH induces a decrease in endogenous cortisol production rates.
Vierhapper
H
H
Department of Internal Medicine III, University of Vienna, Austria.
Nowotny
P
P
Waldhäusl
W
W
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D000818:Animals; D002352:Carrier Proteins / Q000097:blood; D013006:Growth Hormone / Q000494:pharmacology*; D006801:Humans; D006854:Hydrocortisone / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007700:Kinetics; D008297:Male; D051379:Mice
D002352:Carrier Proteins; C027091:cortisol binding globulin; D007334:Insulin-Like Growth Factor I; D000324:Adrenocorticotropic Hormone; D013006:Growth Hormone; D006854:Hydrocortisone