Studies on the effects of tetra-gastrin peptide, secretin, and cholecystokinin-pancreozymin on gastric acid secretion and on the changes of blood sugar, insulin and gastrin contents in plasma

Effects of acetylcholine, tetra-gastrin, secretin, and CCK/PZ on gastric acid secretion, and blood sugar, plasma insulin (IRI) and plasma gastrin level were investigated in rats with induced duodenal fistula. In addition, interactions between these agents on acid secretion were also investigated in rats and partly in man. 1. Acetylcholine, tetra-gastrin and CCK/PZ showed a potent effect of acid secretion, while no stimulating effect was observed by secretin. 2. A transient increase of IRI was demonstrated by CCK/PZ, a slight but not significant decrease by secretin, and no change in IRI was observed by either acetylcholine or tetra-gastrin. 3. Plasma gastrin level persisted to increase after administration of acetylcholine, and a transient increase was observed in the administration of CCK/PZ, while a transient decrease was observed in the administration of secretin. 4. No apparent effect of secretin on acid secretion by tetra-gastrin was seen, while an additive effect on acid secretion was seen between CCK/PZ and tetra-gastrin. 5. In a gastric ulcer patient, administration of secretin did not inhibit acid secretion induced by tetra-gastrin, however, it did inhibit the increase of plasma gastrin level induced by tetragastrin. No change of IRI was detected during gastric acid secretion.