Effect of lipids on glucagon secretion in man.

Animal experiments have suggested a FFA control mechanism for glucagon secretion. In man, the potent effect of FFA on HGH secretion and the similarity of the secretory control mechanisms for HGH and IRG also support a role of FFA in IRG secretion. Our studies in man in which plasma FFA were elevated by either an oral lipid emulsion (Lipomul) or an intravenous lipid suspension (Intralipid)suggest only a minor role of lipids in control of IRG secretion. Plasma FFA and triglyceride elevations did not suppress arginine- or hypoglycemia-induced plasma IRG elevations, but an inhibitory effect of Intralipid on basal plasma IRG concentrations was observed. Although nicotinic acid administration, which caused a depression in plasma FFA, did elevate plasma IRG, the IRG elevation was considered more likely a consequence of stress induced by the drug. The failure of lipids to inhibit IRG secretion at FFA concentrations inhibiting HGH secretion indicates a dissociation in the secretory control mechanisms of the two hormones.