Proteinase-activated receptors in the gastrointestinal system: a functional linkage to prostanoids
- 64 Downloads
Proteinase-activated receptors (PARs), G protein-coupled receptors, play critical roles in the alimentary system. Increasing evidence suggests that endogenous prostaglandins (PGs) mediate some of PARs’ gastrointestinal functions. Systemic administration of the PAR1 agonist protects against gastric mucosal injury through PG formation in rats. PGs also appear to contribute, at least in part, to enhancement of gastric mucosal blood flow and suppression of gastric acid secretion by PAR1 activation. There is also evidence for involvement of PGs in modulation of gastrointestinal motility by PAR1 or PAR2. Importantly, modulation of ion transport by PAR1 or PAR2 in the intestinal mucosal epithelium is largely mediated by PGs. Studies using gastric and intestinal mucosal epithelial cell lines imply that the PAR1-triggered formation of PGs involves multiple signaling pathways including Src, EGF receptor trans-activation and activation of MAP kinases. Collectively, a functional linkage of PAR1 and/or PAR2 to PGs is considered important in the gastrointestinal system.
Keywords:Proteinase-activated receptor (PAR) Gastrointestinal system Prostanoid Prostaglandin E2 Epithelial cell
Unable to display preview. Download preview PDF.