Effect of modified sham feeding and insulin-induced hypoglycemia on function of the proximal stomach

Background/Aim: Animal experiments have shown that vagal cholinergic stimul ation causes an increase in proximal gastric tone, but little is known abou t the effect of vagal stimulation on proximal gastric motor function in hum ans. Vagal cholinergic stimulation can be elicited by modified sham feeding (MSF) or by insulin-induced hypoglycemia. The aim of our study was to inve stigate the effect of MSF and insulin-induced hypoglycemia on the motor and sensory function of the proximal stomach in humans. Methods: Eight healthy volunteers participated in random order in three experiments: (A) control experiment, (B) MSF and (C) intravenous insulin injection. Intragastric vol ume was recorded with a barostat set at a constant preselected pressure lev el (MDP + 2 mm Hg), Pancreatic polypeptide (PP) secretion was measured as a n indicator of cholinergic tone. Results: PP secretion increased significan tly after both MSF (p < 0.05) and insulin administration (p < 0.01), No cha nges in intragastric volume were seen after MSF, while intragastric volume increased significantly in response to insulin-induced hypoglycemia when co mpared to control (290 +/- 43 vs, 148 +/- 24 ml; p < 0.01), No differences in perception scores were seen between the three experiments. Conclusions: Vagal cholinergic stimulation by MSF has no effect on the motor function of the proximal stomach, while insulin-induced hypoglycemia causes a relaxati on of the proximal stomach. Copyright (C) 2000 S. Karger AG. Basel.