The Effect Of Hawthorn Leaves Flavonoids On Isolated Rat Hearts

Objective: To investigate the hemodynamic effects of HLF on isolatedrat heart and the protective effects of HLF on myocardialischemia-reperfusion injury in isolated rat hearts.Methods: ① Via the langendorff reperfused heart model, the effectsof HLF on hemodynamics in isolated rat hearts were observed such asleft ventricle systolic pressure (LVSP),left ventricle diastasis pressur(LVEDP),the odds of the max ascending and changing velocity of leftventricle pressure (±dp/dt max ),arterial pressure (AP),coronary flow(CF),heart rate (HR) . ② Myocardial-ischemia reperfusion injurymodels were established by the ligation of left descending artery for40 min ,followed by reperfusion for 60 min in langendorff rat hearts.HLF was given to myocardium 10 min before ischemia. At the endof reperfusion, coronary effluents were collected in order to analyzeLactate Dehydrogenase (LDH) ,creatine kinase (CK),aspartatetranscarbamoylase (AST) activity as an index of cellular damageinduced by ischemic-reperfusion. The left ventricle washomogenized and tissue content of malonyldialdehyde (MDA),superoxide dismutase (SOD) activity were analyzed.Results : ① The LVSP, AP, and ±dp/dt max decreased as well theLVEDP, CF were increased by the perfusion of HLF . Compared withnormal control , difference is notable (P<0.05,P<0.01), showed thatHLF could decrease cardiac contractility and expande coronary in adose-dependent manner. ② HLF (75, 50, 25mg/L)decreased therelease of AST,CPK,LDH and HLF had protective effects onischemia-reperfusion injury myocardium. Respectively, HLF increasedmyocardial SOD activity and decrease MDA level. HLF alsoincreased coronary blood flow .Conclusions: ① HLF can increase the coronary flow by dilatingcoronary artery. ② HLF exerts negative inotropic effects onmyocardium and leads to a decrease of oxygen consumption . ③ Theischemia/reperfusion injury can be reduced by HLF. Mechanism ofthe protective effect of the HLF may be related to the increase of SOD ,the decrease of MDA and the dilation of coronary artery.