心麻痹液在缺血预处理产生心肌保护效应中的作用研究.doc

心麻痹液在缺血预处理产生心肌保护效应中的作用研究 【关键词】 缺血预处理 Niu Hao，Zhao Jinxian，Zhu Bin Department of internal medicine，Zhongtang People’s Hospital，Dongguan523220. 【Abstract】 Objective To investigate the function of cardioplegia in IPC-induced cardioprotection through comparing the effects of ischemic preconditioning（IPC）and IPC followed by cardioplegia on immature rabbit hearts globally suffered ischemia-reperfusion injury.Methods New Zealand rabbits aged14-21days weighing220-280g were used.The animals were anesthetized and heparinized.Chest was opened and heart was quickly removed and aorta was connected to Langendorff within30s after excision.The hearts were perfused with Krebs-Henseleit buffer balanced with gas mixture（O 2 :CO 2 =95%:5%）at60cmH 2 O（perfusion pressure）.IPC consisted of5min global isˉchemia plus10min reperfusion.Thirty two immature rabbit hearts were randomly divided into four groups:CONⅠ（n=8），was only made globally ischemic by withholding perfusion for30min followed by40min reperfusion;IPC（n=8），IPC and30min noreperfusion followed by40min reperfusion;CONⅡ（n=8），A cardiac arrest was induced with4℃St ThomasⅡcardioplegic solution and a45min nor　eperfusion followed by40min reperfusion;IPC+St.Ⅱ（n=8），IPC，4℃St ThomasⅡcardioplegia and30min noreperfusion followed by40min reperfusion.Coronary flow（CF），HR，left ventricle developed pressure（LVDP），and±dp/dtmax were monitored at equilibration（baseline value）and the5，10，20，30and40min after reperfusion.The values got after reperfusion were expressed as percentage of their baseline valˉue.Myocardial enzyme in the coronary effluent，and myocardial energetic metabolism were also determined.Results The four hemodynamics indexes have not signi ficant difference between the IPC group and the CONⅠ.It took the IPC group much longer time to cardiac ischemia-beating（16.23±1.74min versus13.50±1.82min in controls P0.01）.The CK-MB leakage in IPC group was increased，although the results were not significantly different from control.The myocard