Intestinal Factors in the Control of Insulin Secretion

Abstract

Arterial blood glucose and plasma insulin levels following intrajejunal infusion of glucose were compared with those obtained after intravenous infusion of glucose at the same rate. Despite the lower blood glucose levels there was a much higher plasma insulin response to glucose given jejunally than to glucose given intravenously. Rapid administration of glucose by both routes led to an exaggeration of the inverse relationship between the blood glucose and plasma insulin levels. Similar results were obtained in 2 patients with cirrhosis of the liver who had had end-to-side portacaval shunts performed. Possible explanations of these findings are discussed and reasons are given for believing that a humoral substance is released from the jejunal wall during glucose absorption which acts by stimulating the release of insulin from the pancreatic islet cells.