Plasma catecholamines and postoperative gastric emptying and small intestinal propulsion in the rat.

The role of adrenal medullary discharge of catecholamines on inhibition of gastric emptying and small intestinal propulsion after laparotomy was examined in rats. The rate of movement of a 51Cr-labeled liquid test meal, which had been introduced by gastric intubation, out of the stomach and through the small intestine, was retarded 12 hr after laparotomy. Adrenal demedullation produced a striking decrease in plasma catecholamines and abolished surgically induced elevation of the catecholamines, but had no significant effect on gastric emptying or intestinal propulsion in rats subjected to laparotomy or in the unoperated control animals. Thus circulating catecholamines play little if any role in controlling normal gastroinestinal motility or in the postoperative decrease in rate of gastric emptying and small intestinal motility.