MYOCARDIAL PROTECTION BY PRETREATMENT WITH CRATAEGUS-OXYACANTHA - AN ASSESSMENT BY MEANS OF THE RELEASE OF LACTATE-DEHYDROGENASE BY THE ISCHEMIC AND REPERFUSED LANGENDORFF HEART

The effect of the pretreatment with the powder of crataegus oxyacantha on the release of lactate dehydrogenase (LDH) during ischemia and rep erfusion was studied in an isolated rat heart model. Male Wistar rats were divided into control and crataegus group (for which the standard diet was mixed with a 2% crataegus powder standardized to 2.2% flavono ids). The investigations started 3 months after commencing the treatme nt. The hearts were isolated and a retrograde perfusion was performed at constant pressure according to the technique of Langendorff. The ex perimental protocol comprised 10 min equilibration, 110 min occlusion of the left anterior descending coronary artery, and 30 min reperfusio n. The coronary effluent was sampled for the LDH determination after 5 , 30, 90, 120 and 150 min. The LDH activity, which was initially very low in both groups (control, 16.5 +/- 4.3; crataegus, 26.0 +/- 8.8 mU/ min) increased slightly during the ischemia, and very strongly as soon as the heart was reperfused. However, the increase in the crataegus g roup was significantly lower (1777.3 +/- 451.9 vs control 3795.3 +/- 5 11.9 mU/min, p = 0.01). At the end of the reperfusion period, LDH acti vity decreased markedly but did not reach the ischemic values. The att enuation of the LDH release by crataegus pretreatment suggests a prese rvation of the cell membrane and a protection from myocardial damage.