Journal of pharmacological sciences
-
The cardioprotective effects of the novel sodium/hydrogen exchanger-1 (NHE-1) inhibitor KR-32560 {[5-(2-methoxy-5-fluorophenyl)furan-2-ylcarbonyl]guanidine} were studied in an anesthetized rat model of 30-min ischemia / 2.5-h reperfusion heart injury. KR-32560 (0.01 - 1 microM) dose-dependently inhibited NHE-1-mediated rabbit platelet swelling induced by intracellular acidification. KR-32560 at 0.1 and 1.0 mg/kg (i.v. bolus, given 10 min before ischemia) reduced infarct size from 65.9% (control) to 49.7% and 32.7%, respectively, while reducing the extension of myocardial injury (mm(3)/g of left heart weight) from 405.1 (control) to 302.9 and 185.4, respectively (all P<0.05 vs control). ⋯ KR-32560 dose-dependently reduced ventricular fibrillation (VF) incidence from 19.0 (control) to 9.2 and 1.2 and VF duration from 88.0 s to 34.5 and 2.8 s (all P<0.05, n = 6). KR-32560 also exerted similar effects on reperfusion arrhythmias, except for VPBs. These results indicate that KR-32560 may exert significant cardioprotective effects in ischemia/reperfusion heart injury.