Inhibition of the growth hormone (GH) response to GH-releasing hormone by constant Met-GH infusions.
GH release is controlled by hypothalamic hormones and insulin-like growth factor I, synthesized under the influence of GH, and perhaps also by GH itself. The availability of recombinant Met-GH was the basis for studies aimed at 1) obtaining constant serum GH levels by means of constant Met-GH infusions (40 and 80 ng/kg.min for 6 h), and 2) evaluating the metabolic effects of constant GH levels and, in particular, their effects on the serum GH response to GHRH. In six normal men, both Met-GH infusions increased plasma FFA levels, but did not alter the circulating levels of somatostatin, insulin-like growth factor I, insulin, glucose, cholesterol, and triglycerides. The Met-GH infusions did cause a dose-related inhibition of GHRH-induced GH release. These data indicate that it is possible to maintain constant serum GH levels by means of constant Met-GH infusions at different infusion rates, and that GH inhibits its own release.
Pontiroli
A E
AE
Istituto Scientifico San Raffaele, Universitá degli Studi di Milano, Italy.
Lanzi
R
R
Pozza
G
G
D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D002784:Cholesterol / Q000097:blood; D013006:Growth Hormone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood* / Q000494:pharmacology; D013007:Growth Hormone-Releasing Hormone / Q000008:administration & dosage* / Q000494:pharmacology; D019382:Human Growth Hormone; D006801:Humans; D007262:Infusions, Intravenous; D007334:Insulin-Like Growth Factor I / Q000097:blood; D008297:Male; D011863:Radioimmunoassay; D011994:Recombinant Proteins / Q000008:administration & dosage; D013004:Somatostatin / Q000097:blood; D014280:Triglycerides / Q000097:blood
D001786:Blood Glucose; D011994:Recombinant Proteins; D014280:Triglycerides; D019382:Human Growth Hormone; D013004:Somatostatin; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D002784:Cholesterol