Additive interaction of pentagastrin and secretin on pancreatic growth in rats

Abstract

The role of gastrin in regulating pancreatic growth and its interaction with secretin is unclear. We determined the dose-response relationships of pentagastrin for gastric and pancreatic secretion. Doses that stimulated gastric and pancreatic secretion were given every 8 h for 3 or 5 days; trophic responses of pancreas, oxyntic gland area, duodenum, and colon were compared. Interaction of secretin and pentagastrin on pancreatic growth was measured after 5 days of treatment. Pentagastrin was 250 times less potent for stimulation of pancreatic versus gastric secretion. A submaximal dose of pentagastrin for stimulating pancreatic enzyme secretion doubled pancreatic deoxyribonucleic acid synthesis after 3 days. Pentagastrin caused dose-related increases in pancreatic weight after 3 and 5 days. Pentagastrin had no effect on weight, deoxyribonucleic acid synthesis, or deoxyribonucleic acid content of oxyntic gland area, duodenum, or colon. Secretin had additive effects on pentagastrin-induced pancreatic growth. The pancreas appears to be more sensitive than other organs to trophic effects of pentagastrin. Secretin has additive rather than inhibitory effects on pentagastrin-induced pancreatic growth.