THE ETHANOL AUGMENTATION OF GLUCOSE-INDUCED INSULIN-SECRETION IS ABOLISHED BY CALCIUM ANTAGONISM WITH NIFEDIPINE - NO EVIDENCE FOR A ROLE OF GLUCAGON-LIKE PEPTIDE-1 (GLP-1)

We studied the effect of ethanol and calcium antagonism (nifedipine) o n insulin- (n = 8) and glucagon-like peptide-1 (GLP-1) (n = 6) secreti on in healthy subjects. Four experiments in random order were performe d (control, ethanol, nifedipine, and combination). Intravenous glucose tolerance tests were performed with and without pretreatment with ora l ethanol and nifedipine. Ethanol pretreatment was followed by increas ed insulin (ethanol vs. control; p < 0.01) and C-peptide (ethanol vs. control; p < 0.05) areas after intravenous glucose (0-20 min), indicat ing that ethanol augments insulin secretion. Calcium antagonism with n ifedipine abolished the ethanol augmentation of insulin secretion (ins ulin area 0-20 min, ethanol vs. combination, p < 0.05; and C-peptide a rea 0-20 min, ethanol vs. combination, p < 0.01). The GLP-1 response ( area 0-90 min) was not significantly affected by ethanol.