Parasympathetic innervation and pancreatic secretion: the role of the gastric antrum.

The role of the antrum on vagally mediated pancreatic secretion was studied in 8 conscious dogs prepared with chronic pancreatic and gastric fistulae. After completion of control studies 6 were subjected to antrectomy and 2 to antroneurolysis (to interrupt submucosal nerve connections); secretory studies were repeated. With the animals secreting in response to secretin(0.03 u per kg-min) or secretin with cholecystokinin (0.05 u per kg-min), the following were administered: 1) insulin 0.2 u/kg; 2) atropine 0.2 and 0.4 mg/kg; 3) insulin after atropine. Insulin hypoglycemia elicited a marked enzyme response. Both antrectomy and antroneurolysis markedly reduced (80%) the enzyme response to insulin hypoglycemia. Atropine 0.2 mg/kg abolished the insulin response and at 0.4 mg/kg inhibited (50%) the enzyme response to cholecystokinin; these effects were unaltered by antrectomy or antroneurolysis. These experiments suggest that the pancreatic enzyme response to insulin hypoglycemia is predominantly mediated through the vagal release of antral gastrin. Furthermore, antrectomy and antroneurolysis do not affect the enzyme response to cholecystokinin nor do they alter the inhibitory effects of atropine. The inhibitio- by atropine suggests that a cholinergic background exerts a permissive effect on CCK-mediated enzyme secretion.