Module 7: Figure control of pancreatic secretion
Control of secretion by the exocrine pancreatic acinar cells.
Acetylcholine (ACh) and cholecystokinin (CCK) are two of the major regulators of enzyme and fluid secretion. Control of these two secretory processes occurs through Ca2+ signals that are localized to the apical zone. A mitochondrial firewall helps to ensure that the apical microdomain of Ca2+ is restricted to this apical zone. The Ca2+ signal is generated by a number of release channels: inositol 1,4,5-trisphosphate (InsP3) receptors, ryanodine receptors (RYRs) and the putative nicotinic acid–adenine dinucleotide phosphate (NAADP) receptor (NAADPR). The way in which these different receptors are activated is described in the text.