青钱柳多糖对大鼠心肌缺血再灌注损伤的保护作用

Protective effects of a polysaccharide fromCyclocaryapaliurus on myocardial ischemia-reperfusion injury in rats

目的:探讨青钱柳多糖对大鼠心肌缺血再灌注损伤(MIRI)的保护作用。方法:将50只Wistar大鼠随机分为5组,即假手术组、对照组、青钱柳多糖低剂量组(100 mg·kg-1)、青钱柳多糖中剂量组(200 mg·kg-1)、青钱柳多糖高剂量组(400 mg·kg-1)。连续给药7 d,在末次给药1 h后,对大鼠的冠状动脉左前降支进行结扎手术以复制心肌缺血再灌注损伤模型。检查各组大鼠的心脏功能,并测定血清中肌酸激酶(CK)、乳酸脱氢酶(LDH)和心肌组织中超氧化物歧化酶(SOD)的活性以及丙二醛(MDA)的含量。同时,利用TTC染色法对各组大鼠心肌梗死范围进行测定。结果:与对照组比较,青钱柳多糖能使大鼠心脏的收缩功能得到明显恢复,大幅降低血清中CK和LDH的水平及心肌组织中MDA含量,提高心肌组织中SOD的活性,并有效降低心肌梗死范围(差异均有统计学意义P<0.05)。结论:青钱柳多糖对心肌缺血再灌注损伤大鼠的心肌细胞有保护作用,其作用机制可能与抗脂质过氧化、清除机体自由基有关。

OBJECTIVE To investigate protective effects of a polysaccharide from Cyclocarya paliurus on myocardial ischemia-reperfusion injury （MIRI） in rats.METHODS Fifty Wistar rats were randomly divided into five groups：sham group, control group, Cyclocarya paliurus polysaccharide low, medium and high dose groups. Each group was given oral administration for 7 days. After 1h of last administration, rat model with myocardial ischemia-reperfusion injury was produced by ligating left anterior descending branch of coronary artery. Then cardiac functions were observed in rats with myocardial ischemia. Levels of creatine kinase （CK）, lactate dehydrogenase （LDH） in serum and superoxide dismutase （SOD）, malondialdehyde （MDA） in myocardial tissues were measured. Meanwhile, infarct size was detected by TTC staining.RESULTS Compared to control group, Cyclocarya paliurus polysaccharide could significantly improve cardiac functions, greatly decrease CK and LDH levels in serum and MDA in myocardial tissues, improve SOD activity in myocardial tissues, and effectively reduce myocardial infarct range （P〈0.05）.CONCLUSION Cyclocarya paliurus polysaccharide has beneficial effects on rats with myocardial ischemia-reperfusion injury. Mechanism may be related to inhibition of lipid peroxidation and clearance of free radicals.