Feedback regulation of pancreatic exocrine secretion in animal and man.

This chapter focuses on studies dealing with the feedback mechanism of pancreatic exocrine secretion in animal and man. Clear evidence is presented that this feedback mechanism is working in the rat and the pig and that this feedback is mediated in the rat by the gastrointestinal hormones pancreozymin (enzyme secretion) and secretin (volume and bicarbonate secretion). Two novel peptides have been described--the 'CCK-releasing peptide' originating from the small intestinal mucosa, and the 'monitor peptide' cosecreted together with the enzymes in the pancreatic juice--to account for the stimulation of pancreatic enzyme secretion by the release of CCK. A similar feedback regulation of pancreatic secretion is working in man. It remains as yet controversial whether the feedback in humans is regulated via hormonal or neural pathways. It is also a matter of debate whether this feedback regulation of pancreatic enzyme secretion could be utilized for therapeutic aims in the treatment of pain in patients with chronic pancreatitis.