PROTECTIVE EFFECT OF CRATAEGUS EXTRACT ON THE CARDIAC MECHANICAL DYSFUNCTION IN ISOLATED-PERFUSED WORKING RAT-HEART

The effect of the water-soluble fraction of Crataegus (Crataegus extra ct) on the cardiac mechanical and metabolic function was studied in th e isolated, perfused working rat heart during ischemia and reperfusion . Ischemia (15 min) was produced by removing afterload pressure, and r eperfusion (20 min) was produced by returning it to the original press ure. In the control (no drug) heart, ischemia decreased mechanical fun ction to the lowest level, which did not recover even after the end of reperfusion. Crataegus extract (0.01 or 0.05 %) was applied to the he art from 5 min before ischemia through the first 10 min after reperfus ion. With the high concentration of Crataegus extract (0.05 %) the mec hanical function recovered during reperfusion incompletely without inc reasing coronary flow, but the low concentration of Crataegus extract (0.01 %) did not. In the heart treated with the high concentration of Crataegus extract, the reperfusion-induced recovery of the energy meta bolism was accelerated, and the level of lactate during ischemia was l ower than that in the control heart, although the myocardial levels of free fatty acids during ischemia and reperfusion were not greatly aff ected. These results demonstrate that Crataegus extract (0.05 %) has a cardioprotective effect on the ischemic-reperfused heart, and that th e cardioprotective effect is not accompanied by an increase in coronar y flow.