Аннотация:Activated protein C (APC) regulates the functional activity of mast cells by
reducing release of beta-hexosaminidase, the marker of mast cell degranulation.
APC could modulate the cell secretion of both: the rest mast cells and the
activated cells with degranulators, such as proteinase-activated receptor agonist
peptide (PAR1-AP) and compound 48/80. PAR1 desensitization with thrombin
abolishes the effect of low APC concentration (< or =1,5 nM) on
beta-hexosaminidase release by mast cells. APC, inactivated with
phenilmethylsulfonilftoride (PMSF), did non mimic the enzyme action on mast
cells. The duodenal proteinase, duodenase, activates the peritoneal mast cell via
PAR1. APC abolishes the proinflammatory action of duodenase and PAR1-AP by means
of reducing release of mast cell mediators. Pretreatment of mast cell with L-NAME
abolished these APC effects. Thus, APC-induced decrease of mediator release could
be attributed to NO generation by mast cells. Our data indicate that PAR1 takes
part in the mechanism of regulatory anti-inflammatory APC action.