缺血预适应对肢体缺血-再灌注后骨骼肌损伤和细胞凋亡的影响

目的 探讨缺血预适心(IPC)对肢体缺血-再灌注(LI-R)损伤后骨骼肌的保护机制.方法 雄性Wistar大鼠24只随机分为对照(C)组,缺血-再灌注(I-R)组和缺血预适应(IPC+I-R)组,每组8只.分别测定血浆乳酸脱氢酶(LDH)、肌酸激酶(CK)、活性氧(ROS)、丙二醛(MDA)的含量;测定竹骼肌组织中ROS、MDA、Ca~(2+)、Na~+-K~+-ATP酶、Ca~(2+)-Mg~(2+)-ATP酶、谷胱甘肽过氧化物酶(GSH-P_x)、还原型谷胱甘肽(GSH)的含量,采用免疫组织化学方法检测Bcl-2、Bax、Caspase-3的表达.采用原位末端标记法(TUNEL)检测凋亡指数(AI).结果 与I-R组比较,IPC+I-R组血浆LDH,CK、ROS、MDA及骨骼肌组织中ROS、MDA、Ca~(2+)含量下降,骨骼肌组织中Na~+-K~+-ATP酶、Ca~(2+)-Mg~(26)-ATP酶、GSH-Px、GSH、水平升高,骨骼肌组织Bax、Caspase-3表达明显减弱,Bcl-2表达增强,Bcl-2/Bax比值升高,AI下降.结论 IPC可能通过减少自由基生成和提高自由基清除酶的活性,降低钙超载抑制骨骼肌细胞的凋亡对LI-R后骨骼肌产生保护作用.

Effects of ischemic preconditioning on skeletal muscle ischemia-reperfusion injury and apoptosis on the hind limbs of rats

Objective To study the mechanism of ischemic preconditioning(IPC) protecting the skeletal muscle injury following limb isehemia-reperfusion(LI-R) injury.Methods Twenty-four Wistar rats were randomly divided into three groups of control(group C), I-R, and IPC+I-R, with 8rats each.The contents of lactate dehydrogenase(LDH), creatine phosphate kinase(CK), reactive oxygen species(ROS), and malondialehyde(MDA) in plasma and the values of ROS, MDA,Ca~(2+),Na~+-K~+-ATPase, Ca~(2+)-Mg~(2+)-ATPase, glutathione peroxidase(GSH-P_x), glutathione(GSH) in skeletal muscle were measured.The immunohistoehemistry(IHC) method was used to detect the expressions of Bcl-2, Bax and Caspase-3.Apoptosis was examined by TUNEL.Results Compared with group I-R,the values of LDH,CK,ROS, MDA in plasma were decreased in group IPC+IR.The levels of ROS, MDA,Ca~(2+) in skeletal muscle decreased in group IPC+IR, but the levels of GSH-Px,GSH, Na~+-K~+-ATPase, Ca~(2+)-ATPase increased.The expressions of Bax and Caspase-3 were obviously decreased in group IPC+I-R, while the expression of Bcl-2 was increased.The apoptosis index was lower in group IPC+ IR than that in group I-R.Conclusion IPC has protective effects on skeletal muscle following LI-R injury in rats by reducing the occurrence of apoptosis through alleviating the damage of oxidative and the calcium overload.