β结合素与大鼠心肌缺血再灌注损伤的作用机制

The Mechanism of β-cat and Myocardial Ischemia-Reperfusion Injury(MIRI) in Rats

目的研究大鼠心肌缺血、缺血再灌注、无创性缺血预处理以及氯化锂干预后心肌细胞β结合素的阳性表达率及细胞凋亡指数的变化,以探讨β结合素与心肌缺血、缺血再灌注的关系以及可能机制。方法将入选的60只大鼠随机分为假手术对照组(C)、缺血组(I)、缺血再灌注组(IR)、氯化锂药物预处理组(PPC)。以TUNEL方法评估各组大鼠心肌细胞凋亡情况,以免疫组化方法测定各组大鼠心肌细胞中β结合素的表达,并计算各组大鼠的心肌细胞凋亡指数及β结合素。结果与C组比较,I、IR、PPC四组凋亡指数均升高(P<0.05),各组心肌细胞凋亡指数比较的结果为:IR组>I组>PPC组>C组(各组两两比较均P<0.05);各组心肌细胞β-cat阳性表达率比较的结果为:PPC组>C组>I组>IR组。β-cat阳性表达率与凋亡指数呈负相关,R=-0.90。结论β-cat阳性表达率与凋亡指数呈负相关,提示β-cat可以减少心肌缺血、缺血再灌注引起的细胞凋亡。

Objective To explore the relationship and possible related mechanisms between β-cat ,myocardial ischemia and ischemia reperfusion ,the changes of apoptotic index and positive expression index of β-cat in rats with myocardial ischemia ,ischemia-reperfu-sion ,ischemic preconditioning and lithium chloride intervention were observed respectively. Methods 60 SD （standard ） rats were randomly divided into 5 groups as follows：Control group （C） ,Ischemic group （I） ,Ischemia-reperfusion group （IR） ,Ischemic pre-condition group （IPC） ,Pharmacological preconditioning group （PPC）.The level of myocardial apoptosis was detected by TUNEL , the expression of β-cat was detected by Immunohistochemistry ,the apoptotic index andβ-cat of each group were measured. Results Compared with group C ,in group I ,IR ,IPC and PPC ,the apoptotic indexes were all increased （ P〈0.05）;the comparison of apoptotic index in each group was as follows ：IR group〉I group〉IPC group〉PPC group〉C group ,there were significant differ-ences among groups （ P〈0.05 ）;comparison of the positive expression indexes of β-cat：PPC group〉IPC group〉C group〉I group〉IR group.The positive expression index of β-cat was negatively correlated with AI ,R= -0.90.Conclusions 1.The positive expres-sion index ofβ-cat was negatively correlated with AI.The results indicated that β-cat could reduce apoptosis in the situation of my-ocardial ischemia and ischemia reperfusion.2.The IPC group has strongerβ-cat expression and lower AI than IR and I group ,which indicated the anti-apoptosis effect may have relationship with the stranger expression of β-cat.