The mechanism of insulin secretion after oral glucose administration. VIII. Pancreatic juice insulin excretion after glucose loading and meal ingestion in normal and vagotomized dogs

Abstract

On pancreatic fistula dogs, in the pancreatic juice, immunoreactive insulin has been identified. Insulin excretion is shown to be inhibited by an intravenous glucose load and to be stimulated in a biphasic manner by an oral glucose load or by ingestion of mashed meat. Insulin excretion is reduced 2 months after bilateral truncular vagotomy and the reaction to both oral stimuli is abolished. -- There is no statistical correlation between pancreatic juice insulin and blood glucose, plasma IRI, or plasma amino nitrogen concentrations. Single extrainsular B-cells shown by histologic examination are suggested to be the source of pancreatic juice insulin. Compared to insulin secreted into the portal blood flow, insulin in the pancreatic juice amounts to only 0.1--0.2% of the daily secretory rate of the islets of Langerhans.