Pancreatic secretion

The secretions of the exocrine pancreas, which include digestive enzymes and bicarbonate, affect the digestion and absorption of nutrients. Exocrine pancreatic secretion can influence pancreatic hormone release. The control of both endocrine and exocrine pancreatic function is complex and is highly regulated by both neural and hormonal factors. Pancreatic enzymes are synthesized within acinar cells and packaged into zymogen granules. The hormones secretin and cholecystokinin (CCK) and the vagovagal reflexes that activate cholinergic postganglionic neurons in the pancreas mediate most of the postprandial pancreatic secretion. There is synergistic interaction between vagal CCK and serotonin receptors in mediating pancreatic secretion. Insulin modulates exocrine pancreatic secretion through the acini-islet-acinar axis. Stimulation of secretion normally involves synergistic interactions among intracellular messengers. The regulation of pancreatic secretion depends on a balance between inhibitory and stimulatory influences on the gland, which are exerted through hormones and the autonomic nervous system.