The ryanodine receptor mediates early zymogen activation in pancreatitis
Abstract
Acute pancreatitis is characterized by the pathologic activation of zymogens within pancreatic acinar cells. The process requires a rise in cytosolic Ca2+ from undefined intracellular stores. We hypothesized that zymogen activation is mediated by ryanodine receptor (RYR)-regulated Ca2+ release, because early zymogen activation takes place in a supranuclear compartment that overlaps in distribution with the RYR. Ca2+ signals in the basolateral, but not apical, region of acinar cells observed during supraphysiologic agonist stimulation were dependent on RYR Ca2+ release. Inhibition of RYR or depletion of RYR-sensitive Ca2+ pools each reduced pathologic zymogen activation in isolated acinar cells, but neither treatment affected amylase secretion. Inhibition of RYR also inhibited zymogen activation in vivo. We propose that Ca2+ release from the RYR mediates zymogen activation but not enzyme secretion. The findings imply a role for the RYR in acute pancreatitis.
- Publication:
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Proceedings of the National Academy of Science
- Pub Date:
- October 2005
- DOI:
- 10.1073/pnas.0503215102
- Bibcode:
- 2005PNAS..10214386H
- Keywords:
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- MEDICAL SCIENCES