Biochemical reactions involved in pancreatic enzyme secretion. 2. Inhibitory effects of tetracaine and atropine.

Pancreatic enzyme secretion induced by urecholine or cholecystokinin-pancreozymin (CCK-PZ) is inhibited by tetracaine. If the pancreatic tissue is preincubated with tetracaine then washed out, the subsequent response to CCK-PZ is not affected while that to urecholine is impaired. In contrast with atropine, tetracaine loses its inhibitory potency once secretion has been initiated by urecholine before the addition of the local anaesthetic. Calcium efflux studies have shown that addition of tetracaine in vitro is associated with release of calcium in the incubation medium. This effect on calcium efflux might explain partly the inhibitory action of the drug.