乙酸镁对大鼠心肌缺血-再灌注损伤的保护作用

目的观察乙酸镁对大鼠心肌缺血-再灌注损伤的干预作用及其机制。方法50只SD大鼠随机分为5组：假手术组、缺血再灌注模型组、乙酸镁低剂量组、乙酸镁中剂量组、乙酸镁高剂量组，采用整体大鼠心肌缺血-再灌注损伤模型，结扎冠状动脉左前降支30min后，再灌注60min，实验终点时取血和心肌标本，分别测定血清中Mg^2＋浓度和CK活性和心肌组织Ca^2＋浓度、MDA、SOD含量及Na—K—ATP酶活性等指标。结果与模型组相比，乙酸镁三个不同剂量组血清中Mg^2＋浓度升高，CK活性降低；心肌组织中Ca^2＋浓度降低，MDA含量明显降低，SOD活性及Na—K—ATP酶活性显著升高，并呈剂量依赖性。结论乙酸镁对心肌缺血再灌注损伤具有保护作用，其保护作用机制与减轻心肌细胞钙超负荷，减轻氧自由基损伤，改善心肌细胞能量代谢有关。

Cardioprotective Effects of Magnesium Acetate on Myocardial Ischemia Reperfusion Injury in Rats

Objective This paper has observed the cardioprotective effect and mechanisms of magnesium acetate on myocardial ischemia reperfusion injury in rats. Methods 50 SD rats were randomly divided into five groups: Sham,Control,low-dosage magnesium acetate,media-dosage magnesium acetate,high-dosage magnesium. The model in rats was made by deligating then releasing the suture advanced around the left coronary artery inducing 30 minutes ischemia and 60 minutes reperfusion.When the reperfusion was executed,collecting blood for assaying CK and Mg2 content,and heart samples for determining the activeties of ATPase,and SOD,contents of MDA and Ca2 .Results Compared with control group,the three agents reduced the activities of CK,contents of MDA and Ca2 ,improved the Mg2 content,ATPase and SOD.The dosage dependence was observed from the effect mentioned above. Conclusions Magnesium acetate has protective effects on myocardial ischemia reperfusion injury.The protective effect may be related to relieving calcium overload and clearing oxygen free radical,improving myocardial cell energy metabolism.