Pancreatic and gastric release of somatostatinlike immunoreactivity during intestinal phase of a meal.

The present study was designed to examine pancreatic and gastric D-cell function during the intestinal phase of a liver meal. The intraduodenal instillation of a 20% liver meal (5 ml/min) elicited a significant rise in the plasma levels of somatostatinlike immunoreactivity (SLI) in the pancreatic vein and inferior vena cava, together with the rise in glucagon and insulin levels. The rise in pancreatic vein SLI was not reduced after truncal vagotomy or during atropine infusion. In the stomach, the intestinal liver meal elicited a significant rise in antral but not fundic vein SLI levels. The rise in antral vein SLI was augmented after truncal vagotomy and abolished during atropine infusion, as was the rise in inferior vena caval SLI. In contrast to the protein meal, intravenous infusion of an amino acid mixture elicited a rise in pancreatic vein SLI but not antral or fundic vein SLI. It is concluded that during the intestinal phase of a protein meal, pancreatic and antral but not fundic SLI release is stimulated. The effects of truncal vagotomy and atropine infusion on these responses suggest a close interaction between the vagus and muscarinic cholinergic mechanisms and the D cells of the stomach and pancreas.