Cardiac mast cell stabilization and cardioprotective effect of ischemic preconditioning in isolated rat heart.

This study was designed to investigate the effect of disodium cromoglycate (DSCG), a mast cell stabilizer, on cardioprotective effect of ischemic preconditioning. Isolated rat heart was subjected to 30 min of global ischemia followed by 30 min of reperfusion. Ischemic preconditioning was provided by four episodes of 5-min global ischemia followed by 5 min of reperfusion before sustained ischemia. Ischemic preconditioning and DSCG (10 and 100 microM) treatment markedly decreased the release of lactate dehydrogenase (LDH) and creatine kinase (CK) in coronary effluent and percentage incidence of ventricular premature beats (VPBs) and ventricular tachycardia/fibrillation (VT/VF) during reperfusion. Ischemic preconditioning and DSCG treatment also significantly reduced ischemia/reperfusion-induced mast cell peroxidase (MPO) release, a marker of mast cell degranulation. A significant increase in MPO release was observed immediately after ischemic preconditioning, and the release was found to be inhibited in hearts perfused with DSCG (10 and 100 microM) during ischemic preconditioning. DSCG administered during ischemic preconditioning (DSCG in ischemic preconditioning) attenuated the cardioprotective and antiarrhythmic effects of ischemic preconditioning. DSCG in ischemic preconditioning produced no marked effect on ischemia/reperfusion-induced MPO release. These findings tentatively suggest that DSCG administration during ischemic preconditioning abolishes its cardioprotective effect, perhaps by stabilizing resident cardiac mast cells.