NO参与缺血预处理对大鼠骨骼肌缺血再灌注损伤的保护作用

NO involves in the protective effect of ischemic preconditioning on ischemia/reperfusion skeletal muscle of rat

目的研究缺血预处理(IPC)对大鼠骨骼肌缺血再灌注损伤的保护作用及一氧化氮(NO)是否参与此保护作用。方法采用Wistar雌性大鼠,在左后肢跟部止血,同时使用血流监测仪测股四头肌的血流量,调整止血带的松紧程度,使血流量控制在上止血带前的30%。30只大鼠随机分成3组,分别为缺血再灌注组(n=10)、缺血预处理组(n=10)、缺血预处理+NAME组(n=10)。应用尼克酰胺腺嘌呤二核苷酸黄递酶2+2+(NADH)染色,检测股四头肌各型肌纤维横截面积,钙-腺苷三磷酸酶(Ca-ATPase)染色,观察细胞膜CaATPase分布。透射电镜观测肌细胞的超微结构变化。结果缺血再灌注组出现明显肌纤维破裂溶解,许多白细胞浸润,电镜下线粒体中含有大量空泡变性、肌纤维断裂、溶解和"Z线"排列整齐膜脂质过氧化物的增加。与缺血再灌注组相比,缺血预处理组显示了轻微的损害,正常的纤维和血管变形少,股四头肌各型肌纤维横2+截面积降低,细胞膜Ca-ATPase数量增加。缺血预处理+NAME组与缺血再灌注组相比没有明显改变。结论缺血预处理对大鼠骨骼肌缺血再灌注损伤有明显保护作用,NO参与这一保护作用。

Objective To study if nitric oxide（NO） is involved in the protective effect of ischemic preconditioning on ischemia/reperfusion skeletal muscle of rat. Methods 30 female Wistar rats underwent 4hs of ischemia followed by 60 min of reperfusion by bandage of left inferior limb and divided averagely into three groups： ischemia/reperfusian（I/PC） group, ischemic preconditioning（IPC） group, IPC＋NAME（pretreatment with aminoguanidine, AMG, inhibitor of nitric oxide synthase enzymes）. NADH staining was used to determine the transverse area of quadriceps, Ca^2＋-ATPase staining was applied to observe the distribution of Ca^2＋-ATPase combined points of the muscle fibers, transmission electron microscope was used to observe the ultramicrostructure of muscle rivers. Results The ruptured and dissolved muscle fibers were found with many leukocytes infiltration and increased membrane lipid peroxide in I/P group, but showed slightly injury with more normal fibers and less vascular degeneration and decreased membrane lipid peroxide in IPC group. The transverse area of quadriceps was lower, but the level of Ca^2＋-ATPase positive product was higher in IPC group than in I/P group, with no obvious difference between IPC＋NAME and I/P groups. Conclusion The ischemic preconditioning had protective effect on I/R skeletal muscle, eNOS might be involved in the process.