|
摘要：
目的 研究丙泊酚预处理对大鼠心肌缺血再灌注期间自噬潮的影响及其机制。 方法 采用大鼠在体心肌缺血再灌注损伤模型，将90只雄性SD大鼠采用随机数字表法随机分为5组：①假手术组（Sham）：只穿线不结扎；②缺血再灌注组（IR）③丙泊酚预处理组（P+IR）④PI3K抑制剂A66预处理组（A+IR）⑤丙泊酚、A66预处理组（P+A+IR）。采用结扎冠状动脉左前降支的方法制备心肌缺血再灌注模型。除sham组外，其余各组均缺血30分钟再灌注120分钟。缺血前15min，P+IR组通过股静脉输入丙泊酚15mg/kg/h。A+IR组缺血前1小时腹腔注射A66溶液10mg/kg。P+A+IR组在缺血前1小时腹腔注射A66溶液10mg/kg，缺血前15min再通过股静脉输入丙泊酚15mg/kg/h。模型制备后，取心肌，TTC法染色并计算梗死面积百分比；酶标仪法测定乳酸脱氢酶（Lactate dehydrogenase，LDH）活性,蛋白免疫印迹法检测Ⅱ型微管相关蛋白1轻链3（microtubule-associated protein 1 light chain 3, LC3-Ⅱ）、P62蛋白的表达量；电子显微镜定性观察自噬体、自噬溶酶体的数量。 结果 与I/R组相比，P+I/R与P+A+IR组梗死面积[(26.5±1.3)%、（42.6±1.9）% vs(50.1±3.9)%, P<0.05]显著减小,血清LDH活性降低，LC3II表达水平降低，P62表达水平升高（P<0.05），自噬体、自噬溶酶体明显减少。与P+I/R组相比，P+A+IR组梗死面积[(42.6±1.9)% VS(26.5±1.3)%,P<0.05 ]显著增加,血清LDH活性升高，LC3II表达水平升高，P62表达水平降低（P<0.05），自噬体、自噬溶酶体增加。 结论 丙泊酚预处理激活PI3K/Akt通路，抑制缺血再灌注心肌中自噬潮进行，对大鼠心肌缺血再灌注损伤产生保护作用。
|
|
Abstract: Objective To study the effects of propofol preconditioning on autophagy flux in myocardial ischemia- reperfusion injury of rats and its possible mechanism.
Methods The in vivo rat myocardial ischemia- reperfusion injury model was developed. Healthy adult male SD rats, 280~350g, 90 rats were randomly divided into 5 groups(n=6): sham surgenry group (Sham), ischemia-reperfusion group (I/R), propofol preconditioning group (P+I/R), PI3K inhibitor A66 preconditioning group(A+I/R), Propofol and A66 preconditioning group(P+A+I/R) .Ischemia-reperfusion model was achieved by ligating the anterior descending branch of the left coronary artery (LAD),ischemia for 30min and reperfusion for 2h.Each group underwent 30min ischemia and 2h reperfusion except Sham group. 15mg/kg/h Propofol is infused iv in P+I/R group. 10mg/kg A66 is infused ip in A+I/R group. Myocardial infarct size and lactate dehydrogenase (LDH) levels were examined by 2，3，5-triphenyltetrazolium chloride(TTC) staining and Enzyme standard method at 120min of reperfusion. Expressions of LC3-II and P62 were determined by western blotting. Autophagosome and autophagolysosome were determined by TEM. Results Compared with I/R group, Myocardial infarct size[(26.5±1.3)%，（42.6±1.9）% vs(50.1±3.9)%, P<0.05]，LC3-II and LDH level in P+I/R group was deceased, P62 was incresed (P<0.05) .The number of autophagosome and autophagolysosome was deceased . Compared with P+I/R group, Myocardial infarct size[(42.6±1.9)% vs (26.5±1.3)%,P<0.05 ]，LC3-II and LDH levels were incresed in P+A+I/R group（P<0.05）.The number of autophagosome and autophagolysosome was incresed Conclusions Propofol preconditioning can inhibit autophagy flux by activating PI3K/Akt pathway during ischemia-reperfusion in rat herats ,which may play a role in its cardiopretective mechanism during ischemia-reperfusion injury.
|
