Stimulation of the exocrine pancreas via a third CCK-receptor subtype?
Publikation/Tidskrift/Serie: Livestock Science
Förlag: Elsevier Science B.V.
The physiological role of the cholecystokinin1 receptor (CCK1R) and the cholecystokinin/gastrin receptor (CCK2R) in the enzyme release from the exocrine pancreas in various mammal species has been debated. Experiments in pigs have indicated that physiological levels of cholecystokinin-33 (CCK-33) elicit pancreatic enzyme release via CCK2Rs located in the gastro-duodenal region. Since gastrin and CCK have similar affinity for the CCK2R, the aim was to examine if gastrin can elicit a similar enzyme response as CCK, after infusion via the gastric artery. Weaned pigs were anaesthetised and surgically prepared with appropriate catheters. Pentagastrin (n = 6) or CCK-3 3 (n = 6), 13 pmol/kg, was infused via the gastric artery into the gastro-duodenal region and 20 min. later 130 pmol/kg of the same hormone was infused via the jugular vein to the general circulation. Pancreatic juice was collected in intervals after each infusion and analysed for its protein and enzyme (trypsin) content. CCK-33 gave rise to significantly higher protein and trypsin output compared to pentagastrin for both doses and infusion routes. The results indicate that low doses of CCK-33 infused to the duodenal region do not stimulate the exocrine pancreas via the CCK2R since the result can't be reproduced with pentagastrin. Since previous studies have indicated that CCK1R is not involved the present results indicate that a third CCK-receptor subtype might be involved in the stimulation of the exocrine pancreas.
- Biology and Life Sciences
- exocrine pancreas
- cholecystokinin/gastrin receptor
- ISSN: 1871-1413