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 bicarbonate 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 × 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.