Effects of 2-nicotinamidoethyl nitrate (SG-75) on pancreatic secretion in the isolated, blood-perfused pancreas of the dog.

1. The effects of 2-nicotinamidoethyl nitrate (SG-75) on the secretion of pancreatic juice were compared with those of acetylcholine, secretin and pancreozymin in the isolated, blood-perfused dog pancreas. 2. Intra-arterial administration of SG-75 (0.3-3 mg) elicited a dose-dependent increase in pancreatic secretion. Acetylcholine (10-100 micrograms), secretin (0.03-0.3 units) and in pancreozymin (0.1-1.0 units) also elicited increased secretion. 3. Secretory responses to acetylcholine were inhibited by treatment with atropine, while SG-75-, secretin-, and pancreozymin-induced secretions were not modified. 4. Bicarbonate concentrations in pancreatic juice induced by SG-75 and secretin were increased in a dose-dependent manner. However, there were slight changes with acetylcholine or pancreozymin. 5. Amylase activity in pancreatic juice was increased by SG-75, acetylcholine and pancreozymin, but was decreased by secretin. 6. These results suggest that SG-75 stimulates pancreatic secretion by acting both on the acinar and ductular cells of the dog pancreas.