Effects of insulin and pancreatic polypeptide on gastric somatostatin release

Effects of arginine and such pancreatic hormones as insulin and pancreatic polypeptide on gastric somatostatin release from the isolated perfused rat stomach were studied. The stomach was isolated from a fasted rat by a modification of the method of Lefébvre and was perfused with 4.6% dextran Krebs-Ringer biocarbonate buffer containing 5.5 mM glucose. Both insulin and pancreatic polypeptide (10(-10), 10(-9), and 10(-8) M) caused a significant decrease in gastric somatostatin secretion. Insulin (10(-10) M), furthermore, inhibited the glucagon (5 x 10(-8) M)-induced somatostatin response. Arginine (10 and 19 mM) failed to elicit any significant change of somatostatin release. These results suggest that gastric somatostatin release is affected by pancreatic hormones.