Effects of growth hormone-releasing hormone on the secretion of islet hormones and on glucose homeostasis in lean and genetically obese-diabetic (ob/ob) mice and normal rats

摘要: The effect of synthetic human growth hormone-releasing hormone(1-40) (hGHRH-40) on the function endocrine pancreas and glucose homeostasis in lean genetically obese-diabetic (ob/ob) mice normal rats has been examined. addition 1 mumol hGHRH-40/1 to incubated islets from increased insulin release by 90 37% at 5.6 16.7 mmol glucose/l respectively. Lower concentrations hGHRH-40 did not affect release. (1 mumol/l) pancreatic polypeptide 50% glucose/l. A range nmol/l-1 reduced glucagon 42-73% glucose/l, 38-70% Somatostatin was (eightfold) glucose/1, but nmol somatostatin (by greater than 50%). At glucose/litre 0.01-1 (three- fourfold), produced a reduction 50%. In vivo, administration (50 micrograms/kg body weight i.p.) fasted ob/ob alter basal plasma insulin, or responses concomitant i.p. challenge. Intravenous injection (20 weight) anaesthetized hepatic portal vein. lower dose (0.2 micrograms/kg) ineffective, neither altered glucose.(ABSTRACT TRUNCATED AT 250 WORDS)