Potentiated effect of vagal stimulation and hormonal agents on pancreatic exocrine secretion in dogs

Chronic experiments were made on eighteen dogs with Thomas pancreatic fistula and gastric fistula. Both in chronic and acute experiments the degenerated right cervical vagus nerve was stimulated by electrical shock and the endogenous secretin and CCK was released by means of duodenal acidification (D. A.). The exogenous secretin, atropine and lidocaine were infused to analyse the interrelationship of neurohormones in the pancreatic exocrine secretion. The results were as follows. In chronic experiments the pancreatic secretory latency was shorter and volume larger than that in acute experiments induced by D. A. The difference is very significant (P less than 0.001). Both vagotomy and atropine significantly inhibited pancreatic secretion induced by D. A. (P less than 0.01). Lidocaine infused into duodenum inhibited pancreatic secretion induced by D. A. as well. When vagal stimulation was combined with D. A., either simultaneously or successively, the pancreatic secretion was increased more than the additive sum obtained by separate action of vagal stimulation and D. A. or secretin. In view of the above-mentioned facts, the author suggests that vagal impulses combined with D. A. or secretin act on the pancreatic exocrine secretion, and that the interaction of nerve and hormones appear to be mutually potentiated.