Regulation of the pancreas
The pancreas, localized in the retroperitoneum, plays an important role in the digestion and uptake of food. The endocrine pancreas is formed by the islets of Langerhans, which secrete insulin and glucagon. The exocrine pancreas includes the acinar cells which secrete pancreatic juice. This juice contains a variety of enzymes:
- Buffer solution with bicarbonate and phosphate buffers, which restore the pH
- Alpha-amylase, which breaks down carbohydrate chains
- Pancreatic lipase, which breaks down lipids into fatty acids
- Nuclease, which breaks down nucleic acids
- Proteolytic enzyme, for the digestion of proteins
Upon arrival of containing food containing lipids, proteins, and glucose in the duodenum (1), the cells in the wall of the duodenum release cholecystokinin (CCK) and gastric inhibitory peptide (GIP) into the circulation (2). CCK stimulates the release of pancreatic enzymes into the intestine (3). GIP stimulates the secretion of insulin by the pancreatic islets into the circulation (4).
The most sensitive and specific test to diagnose chronic pancreatitis is:
Female, 40 years, has daily abdominal pain. ERCP: normal bile ducts; pancreatogram: definite "mild" chronic pancreatitis. No alcohol and no FH of pancreatitis. Which of the following is true regarding this patient?
Extra info: The best pain response to pancreatic enzyme supplements has been seen in females with mild, idiopathic pancreatitis. Uncoated preparations that are active in the duodenum appear to give the best response. Enzyme supplements are thought to work via negative feedback inhibition of pancreatic secretion. Orally administered proteases inhibit CCK-releasing peptide in the duodenum. This inhibits the release of CCK and decreases pancreatic secretion.