ENTERAL PANCREATIC-ENZYME FEEDBACK INHIBITION OF THE EXOCRINE SECRETION OF THE HUMAN TRANSPLANTED PANCREAS

The mechanism of regulation of negative feedback inhibition of the exocrine pancreas and its possible role in decreasing the exocrine secretion of the grafted human pancreas is unknown. To evaluate this we studied the effect of oral pancreatic enzymes on the stimulated transplanted pancreatic exocrine secretion in eight patients with allograft pancreaticocystostomies. After an 8-hr fast, all graft exocrine secretions via graft stent, fistula, and urinary anastomosis were collected for a 1-hr basal period. A standard 300-ml Lundh test meal was then ingested, and all exocrine secretions were collected in 30-min intervals for 3 hr. This test was repeated with 6 capsules of pancrelipase (24,000 units of lipase, 120,000 units of amylase, and 150,000 units of protease) given with the Lundh test meal. Stent, urine and fistula volume, amylase, and pH were measured for each collection period. The total 3-hr amylase secreted after the test meal and the test meal plus pancrelipase were compared. The period of peak amylase secretion after the test meal alone was compared with the same period after the test meal plus pancrelipase and the premeal basal period. The total amylase decreased 34% from 5550+/-1000 to 3680+/-740 IU/3 hr (P<.03) with pancrelipase. The peak amylase secretion decreased 63% from 1520+/-271 to 567+/-185 IU/30 min (P<.02) with the addition of pancrelipase to the test meal. Pancrelipase eliminated all meal-stimulated amylase secretion with the mean secretion 16% below the basal secretion of 674+/-117 IU/30 min. We conclude that pancreatic negative feedback inhibition significantly decreases meal-stimulated and basal exocrine secretion in the transplanted human pancreas.