The role of the exocrine pancreas in the stimulation of insulin secretion by intestinal hormones

Summary In 11 non-diabetic patients with clinical and laboratory evidence of chronic exocrine pancreatic insufficiency, the effect of intestinal hormones secretin and pancreozymin upon insulin secretion, blood sugar, free fatty acids and glycerol was studied and compared with the findings obtained in 30 normal volunteers. — In the patients suffering from exocrine pancreatic insufficiency the above mentioned enterohormones did not elicit any increase in serum insulin although insulin secretion after i.v. glucose loads was perfectly undisturbed. Obviously, the mediator inducing insulin release following secretin and pancreozymin in man depends on intact exocrine pancreatic tissue. As had been expected, no differences in the serum-insulin responses to oral and intravenous glucose, as found in normals, were established in these patients. From theses results it is inferred that similarity of plasma insulin changes after oral and parenteral glucose loads might hint at an early impairment of exocrine pancreatic tissue function. That implies, that a (hypothetical) Glucose receptor of the-cell or its surface works more or less independently of both the exocrine pancreatic tissue and the intestinal hormones. On the other hand, the Entero-receptor of the-cell responding to the insulin-stimulating action of intestinal hormones, such as secretin and pancreozymin, is likely to be more or less dependent upon sufficient amounts of intact exocrine pancreatic tissue.Supported by Deutsche Forschungsgemeinschaft, Bad Godesberg, Germany (Pf 38/24).