神经型一氧化氮合酶在小鼠心肌缺血预处理中的作用  

Effect of nNOS During Myocardial Ischemic Preconditioning in Mice

作　　者：卢晓梅[1] 张海鹏[1] 

机构地区：[1]中国医科大学基础医学院病理生理学教研室,辽宁省沈阳市110001

出　　处：《中国动脉硬化杂志》2012年第5期451-454,共4页Chinese Journal of Arteriosclerosis

摘　　要：目的应用神经型一氧化氮合酶(nNOS)基因敲除小鼠和nNOS抑制剂,探讨nNOS对心肌缺血预处理后心肌细胞凋亡的影响。方法实验分为野生型缺血再灌注组(WT IR)、野生型缺血预处理组(WT IP)、野生型缺血预处理L-VNIO处理组(WT IP+L-VNIO)、基因敲除鼠缺血再灌注组(KO IR)和基因敲除鼠缺血预处理组(KOIP)。采用冠状动脉左前降支结扎法建立小鼠缺血再灌注损伤模型,缺血再灌注组缺血30 min再灌注3 h,缺血预处理组分别经缺血5 min再灌注5 min连续三个循环后,再缺血30 min再灌注3 h,观察TUNEL染色和Caspase-8、Caspase-9、Caspase-3的活性变化,并用Western Blot法观察Bax、Bcl-2和Fas蛋白的表达情况。结果与WT IR组相比,WT IP组小鼠TUNEL阳性细胞数目减少,Caspase-8、Caspase-9和Caspase-3活性降低,Bax和Fas蛋白表达显著降低,Bcl-2表达显著增加(P<0.05)。而在KO IP组,与KO IR组相比,TUNEL阳性细胞数目和Caspase活性显著增加,Bax和Fas表达显著增高,Bcl-2表达显著降低(P<0.05)。结论 nNOS在心肌缺血预处理时发挥抑制心肌细胞凋亡的作用。Aim Using neuronal nitric oxide synthase （nNOS） knockout mice and nNOS inhibitor to investigate the effect of nNOS during myocardial ischemic preconditioning. Methods Mice were divided into wild-type ischemia- reperfusion group （WT IR）, wild-type ischemic preconditioning group （WT IP）, wild-type L-VNIO treatment group （WT IP ＋ L-VNIO）, nNOS -/- mice ischemia-reperfusion group （ KO IR）, nNOS-/- mice ischemic preconditioning group （ KO IP）. They were subjected to 30 minutes of ischemia by left descending branch of coronary artery ligation followed 3 hours reperfusion. IP was induced by 3 cycles of 5 minutes ischemia and reperfusion before 30 minutes ischemia. After 3 hours reperfusion, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL） staining and activities of caspase-8, caspase-9, caspase-3, Bax, Bcl-2 and Fas expression were measured. Results In WT group, com- pared with IR group, TUNEL positive cells, caspase-8, caspase-9, caspase-3 activities and Bax and Fas protein expression were significantly decreased, Bcl-2 expression was significantly increased （P 〈 0. 05）. In KO group, compared with IR group, TUNEL positive cells, caspase-8, caspase-9, caspase-3 activities and Bax and Fas protein expression were signifi- cantly increased, Bcl-2 expression was significantly decreased （P 〈 0. 05）. Conclusion nNOS was involved in myo- cardial ischemic preconditioning by reducing myocardial apoptosis.

关 键 词：神经型一氧化氮合酶 缺血预处理 细胞凋亡 

分 类 号：R363[医药卫生—病理学]