Cardioprotective effects of FK409, a nitric oxide donor, after isolated rat heart preservation for 16 hours

BACKGROUND: We examined the cardioprotective effects of FK409, a nitric oxide donor, after isolated rat heart preservation. METHODS: FK409 was administered to the hearts in pretreatment (FK409-1 group), during ischemia (FK409-2), or during reperfusion (FK409-3). The combined nitrate and nitrite level, coronary flow, cardiac function, coronary vasodilatory response, creatine kinase (CK), and myocardial water content were evaluated after the hearts had been preserved in University of Wisconsin solution at 0 degrees C for 16 hours. RESULTS: The release of nitrate and nitrite increased in reperfusion between the 20-to-40-second measurement and the measurement at 40 minutes, and the recovery of cardiac function was significantly improved in the FK409 groups. The coronary vasodilatory response to acetylcholine chloride was enhanced in the FK409-1 and FK409-2 groups. CK release decreased in FK409 groups after 15 minutes in reperfusion. CONCLUSIONS: This study suggests that FK409 has the best protective effect on cardiac function and coronary endothelial function when it is administered in the ischemic period, a less protective effect when administered during pretreatment, and the least protective effect when FK409 is given during reperfusion after heart preservation for 16 hours.