Effect of Oral Glucose Administration on Plasma Growth Hormone-Releasing Hormone (GHRH)-Like Immunoreactivity Levels in Normal Subjects and Patients with Idiopathic GH Deficiency: Evidence that GHRH Is Released Not Only from the Hypothalamus but Also from Extrahypothalamic Tissue*

摘要: Using a specific and sensitive RIA for GH-releasing hormone (GHRH), we examined the effect of oral administration 75 g glucose on peripheral plasma GHRH-like immunoreactivity (GHRH-LI) in normal subjects (n = 12) patients with idiopathic GH deficiency (IGHD) 6). The had two peaks GHRH-LI after administration. initial peak levels occurred 30-150 min ingestion corresponded to an increase blood glucose. increment 30 [7.4 +/- 2.4 (+/- SEM) pg/ml] was significantly higher (P less than 0.05) that during control study. Second 3.5-6 h ingestion, mean 5 9.4 pg/ml. This second rise coincided significant reactive hypoglycemia. hypoglycemia were absent IGHD, whereas first appeared shortly these as well subjects. In addition, produced by iv injection regular insulin (0.1 U/kg) not accompanied increases insulin-induced resulted elevations both These findings suggest is derived from hypothalamus extrahypothalamic source(s); GHRH released ingestion; secretion stimulated