Pancreatic Secretory Response to Intestinal Stimulants: A Review

Abstract

Singer MV. Pancreatic secretory response to intestinal stimulants. Scand J Gastroenterol 1987, 22(suppl 139), 1-13In humans and many laboratory animals, protein digestion products such a s peptides and amino acids and fat digestion products such as fatty acids and monoglycerides are potent intestinal stimulants of pancreatic cnzymc secretion. The pancreatic enzyme response to these intestinal stimulants is related to thc pcrfuscd load (amount per unit time) rather than to concentration. Both neural and hormonal pathways mediate the enzyme response t o thesc intestinal stimulants. Enteropancreatic, cholinergic, vago-vagal reflexes are probahly the most important mediators of the enzyme response to low loads of amino acids and fatty acids; hormones, such ;IS cholecystokinin, seem to be the major mediators of the response to high loads of amino acids and fatty acids. Under physiological conditions it is prohahly thc interplay o f neural and hormonal mechanisms which regulates the pancreatic response to these stimulants. Gastric acid is the major regulator of postprandial pancreatic bicarbonate secretion. Secretin released by HCI is probably the most important physiological hormonal mediator of postprandial pancreatic bicarbonate secretion; its effect heing potentiated by extrinsic (vagal) and intrinsic (intrapancreatic) cholincrgic nerves and rclease of other hormones, such as cholecystokinin. , vagal and splanchnic; pancreatic bicarbonate and enzyme response; sccretin Pro6 sirarsklinik, Hufelandstr. 55, 0-4300 Essen I , FRC Dr. Manfred V . Singer, Ahteilung Casrroenrrologie, Medizinische Unioer-Scand J Gastroenterol Downloaded from informahealthcare.com by University of Sydney on 01/03/15 For personal use only. Scand J Gastroenterol Downloaded from informahealthcare.com by University of Sydney on 01/03/15 For personal use only. No effect No effect No effect Depressed (low loads) Scand J Gastroenterol Downloaded from informahealthcare.com by University of Sydney on 01/03/15For personal use only.

Low Fecal Elastase: Potentially Related to Transient Small Bowel Damage Resulting from Enteric Pathogens

“…In normal condi- tions, both neural (entero-pancreatic, cholinergic, vagovagal reflexes) and hormonal (cholecystokinin) pathways mediate the pancreatic enzyme response to intestinal stimulants. CCK seems to be the major mediator of the response to high loads of amino acids and fatty acids (19). Immuno-histochemistry identified approximately 1650 CCK cells per cross-section in the duodenum of humans (20) and jejunal mucosal integrity is necessary for the normal secretion of enteric hormones by the respective cells located in the small bowel mucosa (10).…”

Effects of dietary lipid levels on growth, survival and lipid metabolism during early ontogeny of Pelteobagrus vachelli larvae

“…In sea bass, pancreatic lipase activity increased with dietary triglyceride level ranging from 13% to 23%, showing a threshold, around 20% triglycerides, at which the maximum lipase activity and messenger RNA level were reached (Cahu et al, 2003). However, it has been suggested that the intestinal receptors for intraluminal stimulants require only a very low concentration for activation, meaning that the length of the intestine exposed to these products is the main determinant of pancreatic secretory response (Singer, 1987). If fish larvae showed similar response, the ingestion rate of the diet might also play a major role in determining lipase activity.…”

Exocrine pancreatic function during cold blockade of the vagus in chronic experiments on calves

“…The effect of section of the vagus nerves on the response of the pancreas to secretin has produced conflicting results, from an unchanged response or a reduced response to no response at all (for references see Grundy, Hutson & Scratcherd, 1983). The contribution of the vagus nerves to the control of pancreatic secretion varies from species to species (for references see Harada, Nakagawa &Kato, 1982 andSinger, 1987). In an attempt to differentiate between vagal and hormonal control, both pharmacological and nerve section have been used.…”