左旋卡尼汀心脏停搏液对大鼠离体心肌保护作用的研究

Protective Effect of L-Carnitine in Cardioplegic Solution on Isolated Rat Hearts

目的:观察含左旋卡尼汀(L-CN)冷停搏液对大鼠缺血心肌的保护作用。方法:32只雌性Wistar大鼠随机分为L0、L2.5、L5和L10共4组(n=8),STH液中分别含有L-CN0、2.5、5和10mmol/L。麻醉后开胸取出心脏,立即连于Langendorff灌注装置,制备上述4种心脏停搏液诱导心脏停搏的心脏缺血再灌注模型。分别取停搏前、再灌注15和30min时冠脉流出液2mL检测乳酸脱氢酶(LDH)、肌酸激酶(CK)。实验末留取心尖部心肌组织,检测三磷酸腺苷(ATP)、丙二醛(MDA)和超氧化物歧化酶(SOD)含量。结果:停搏前各组LDH、CK差异无统计学意义(P>0.05),再灌注后各组LDH、CK均有增加(P<0.01);L-CN组的增加幅度明显小于对照组,且随L-CN浓度的增加,增加幅度减少(P<0.05)。加L-CN各组心肌组织ATP、SOD含量明显增高,MDA含量明显下降(P<0.05)。结论:L-CN加入St.Thomas'Ⅱ(STH)停搏液能减轻缺血-再灌注心肌损伤。

Objective： To observe the protective effect of L-Carnitine （L-CN） in cardioplegic solution on isolated rat hearts. Methods： Thirty-two female Wistar rats were randomly divided into four groups （n=8 for each group） ,group LO（no LCN in cardioplegic solution ）, L2.5 （2.5 mmol/L L-CN in cardioplegic solution ）, L5 （5 mmol/L L-CN in cardioplegic solution ）, L10 （ 10 mmol/L L-CN in cardioplegic solution）. After anesthesia heart was resected from the thoracic cavity of rat, and connected to Langendorff perfusion apparatus immediately. The myocardial ischemic/reperfusion model was produced by different cardioplegic solution. Two mL of coronary flow was taken in each heart to detect myocardial leak enzyme lactate dehydrogenase （LDH） and creatine phosphokinase （CK）. Small pieces of heart tissue at the apex were obtained at the end of experiment. The content of adenosine triphosphate （ATP）, malondialdehyde （MDA） and superoxide dismutase （SOD） were detected in myocardium. Results： There were no significant differences in LDH and CK before hearts stopped beating in all the groups （P 〉 0.05）. After reperfusion,there were increased LDH and CK in 4 groups （P 〈 0.01,respectively）. The increased LDH and CK were significantly lower in L-CN group than that of control group, and the increasing tendency decreased with the increase of L-CN concentration （P 〈 0.05 ）. The contents of ATP and SOD were significant higher, and MDA content was significant lower in groups with L-CN than those in control groups （P 〈 0.05 ）. Conclusion： L-CN added into St.Thomas＇ Ⅱ cardiopledic solution can improve cardiac function after ischemia-reperfusion injury.