Abstract
Background & Aims: Protease-activated receptor 2 can be stimulated by interstitially released trypsin during acute inflammation of the pancreas. In this study, we investigated the roles of pancreatic and circulatory protease-activated receptor 2 in the pathogenesis of acute pancreatitis by using in vitro and in vivo model systems. Methods: Physiological and pathologic effects of protease-activated receptor 2 activation were measured in isolated pancreatic cells and in rats with experimental pancreatitis. Consequences of protease-activated receptor 2 activation on the systemic and inflammatory responses were measured after treatments with trypsin or protease-activated receptor 2-activating peptide. Results: Stimulation of protease-activated receptor 2 in rat pancreatic acinar cells activated short-lasting (Ca 2+ signaling) and long-lasting (extracellular signal-related kinase) signaling pathways and protected the cells against bile-induced cell damage. More importantly, protease-activated receptor 2 activation ameliorated the pathologic effects observed in the in vivo model of cerulein-induced pancreatitis. Trypsin in the circulation of rats with taurocholate-induced severe acute pancreatitis reached levels sufficient to activate endothelial and immune cells to stimulate nitric oxide and interleukin-8 production, respectively. Most notably, activation of systemic protease-activated receptor 2 by circulating protease-activated receptor 2 agonists induced a hemodynamic response pattern similar to that observed in rats with severe acute pancreatitis. The effects of protease-activated receptor 2 agonists and acute pancreatitis were not additive. Conclusions: These findings suggest that protease-activated receptor 2 may have a dual role in acute pancreatitis: protecting acinar and duct cells against pancreatitis-induced cell damage while mediating or aggravating the systemic complications of acute pancreatitis, which are the major cause of mortality in the early phase of necrotizing pancreatitis.
Original language | English (US) |
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Pages (from-to) | 1844-1859 |
Number of pages | 16 |
Journal | Gastroenterology |
Volume | 126 |
Issue number | 7 |
DOIs | |
State | Published - Jun 2004 |
ASJC Scopus subject areas
- Hepatology
- Gastroenterology