How does pancreozymin work on the pancreas and the stomach?

Abstract

The purpose of this study was to clarify the interaction between pancreozymin (PZ) and cholinergic agents on the pancreatic and gastric acid secretion.
In the experiments of the exocrine pancreas, continuous secretin infusion was done to sustain basal pancreatic flow and the effect of PZ on pancreatic enzyme secretion was observed on 16 conscious dogs with or without simultaneous administration of a cholinergic agent, methacholine.
On the other hand, the effect of PZ on gastric acid secretion was investigated using three different kinds of gastric pouches on 17 concious dogs.
Results obtained were as follows
I Exocrine Pancreas
1) There was no significant difference in pancreatic enzyme secretion between vagal innervated group and denervated group.
2) PZ stimulated enzyme secretion from the gland when administered with methacoline simulatneously if doses of both stimulants were not so large; and if they were administered in large amounts, a mutual inhibition on pancreatic enzyme secretion was observed.
3) Atropine, an anticholinergic agent, remarkably blocked the pancreatic enzyme response which was provoked by the intravenous administration of PZ.
II Gastric acid secretion
1) Regardless of the difference of gastric pouch, (Simple gastric fistula, Heidenhain pouch or Double pouch) PZ stimulated gastric acid secretion.
2) PZ, when given with methacholine brought more amount of gastric acid secretion than when it was administered alone.
3) PZ remarkably inhibited gastric acid secretion induced by extrinsic administration of gastrin or by intrinsic release of gastrin.
4) PZ also inhibitted gastric acid secretion induced by histamine.
These observations lead us to a conception that nervous and humoral factors keep an intimate co-relation on the pancreatic enzyme secretion because it was suggested that both stimulants worked on the same receptor-site in the gland.
As for the effects of PZ on gastric acid secretion, it was suggested that PZ itself stimulated oxyntic cells of the stomach and that PZ had a possibility to be enterogastrone as it inhibitted the gastric acid secretion induced by gastrin or by histamine.