基于PI3K/Akt信号通路研究胰岛素对糖尿病大鼠心肌缺血再灌注损伤的保护作用  

Protective effect of insulin on myocardial ischemia-reperfusion injury in diabetic rats based on PI3K/Akt signaling pathway

作　　者：杨进[1] 马水根 徐朝军[1] 刘智[3] 倪广生 Yang Jin;Ma Shuigen;Xu Zhaojun;Liu Zhi;Ni Guangsheng(Department of Cardiothoracic Surgery, The First Affiliated Hospital of Hunan University of Traditional ChineseMedicine, Changsha 410007, China;Department of Gy necology Oncology, Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha 410013 , China;Department of Anesthesiology,The First Affiliated Hospital of Hunan University of Traditional Chinese Medicine, Changsha 410007,China)

机构地区：[1]湖南中医药大学第一附属医院心胸外科,长沙410007 [2]中南大学湘雅医学院附属肿瘤医院妇瘤科,长沙410013 [3]湖南中医药大学第一附属医院麻醉科,长沙410007

出　　处：《中国医师杂志》2019年第3期364-367,372,共5页Journal of Chinese Physician

基　　金：湖南省教育厅基金(16C1208)~~

摘　　要：目的研究胰岛素对糖尿病大鼠心肌缺血再灌注损伤磷脂酰肌醇3-激酶/蛋白激酶B(PI3K/Akt)信号通路的影响。方法采用高糖高脂饮食+腹腔注射链脲佐菌素(40 mg/kg)制备糖尿病大鼠模型,随机分为糖尿病假手术组(A组)、糖尿病缺血再灌注组(B组)、糖尿病缺血再灌注胰岛素处理组(C组)及糖尿病缺血再灌注胰岛素+Wortmaninn(PI3K抑制剂)处理组(D组),每组10只。糖尿病大鼠心肌缺血再灌注模型:于左胸第三、四肋间暴露心脏,距左心耳下缘2 mm处用5-0无菌缝合线结扎左冠状动脉前降支(LAD)及心大静脉30 min,然后恢复灌注120 min。结扎前20min,D组经股静脉予Wortmannin(15μg/kg),其余3组予等量的生理盐水,结扎前10 min,C、D两组予皮下注射胰岛素(2 U/kg),A、B两组皮下注射等量的生理盐水。再灌注120 min后采集动脉血测血清肌酸激酶MB(CK-MB)、肌钙蛋白I(c Tn I)水平,同时采用Western blot检测心肌组织PI3K、磷酸化Akt蛋白表达的情况。结果与A组相比,B组血清c Tn I、CK-MB水平增高,心肌组织PI3K、磷酸化蛋白激酶B(p-Akt)表达水平下降,差异均有统计学意义(P <0. 05);与B组相比较,C组血清c Tn I[(0. 89±0. 26)μg/L]、CK-MB[(9. 24±3. 16)μg/L]水平降低,心肌组织PI3K(0. 341 8±0. 031)、p-Akt(0. 673 1±0. 028)蛋白表达水平增高,差异有统计学意义(P <0. 05);与C组比较,D组血清c Tn I[(1. 16±0. 29)μg/L]、CK-MB [(12. 57±3. 01)μg/L]水平增高,心肌组织PI3K (0. 292 7±0. 036)、p-Akt(0. 531 4±0. 030)蛋白表达下调,差异有统计学意义(P <0. 05)。结论胰岛素能够降低糖尿病大鼠心肌缺血再灌注损伤血清CK-MB、c Tn I的水平,可能是通过激活PI3K/Akt信号转导通路,抑制心肌酶释放,改善糖尿病大鼠心肌缺血再灌注损伤从而发挥保护心肌细胞的作用。Objective To study the effect of insulin on phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway in diabetic rats with myocardial ischemia reperfusion injury. Methods Diabetic rats were induced by high-sugar and high-fat diet plus intraperitoneal injection of streptozotocin (40 mg/kg). They were randomly divided into diabetic sham group (group A), diabetes ischemic reperfusion group (group B), diabetes ischemic reperfusion insulin treatment group (group C) and diabetic ischemia reperfusion+ insulin Wortmaninn (PI3K inhibitors) group (group D), 10 in each group. Myocardial ischemia reperfusion model in diabetic rats: heart was exposed between the third and fourth ribs of the left chest, 2 mm from the lower edge of the left atrial ear, and 5-0 sterile suture was used to ligate the anteri-or descending coronary artery (LAD) and the great cardiac vein for 30 min, and then the perfusion was resumed for 120 min.Wortmannin (15 μg/kg) was given through femoral vein 20 min before ligation in group D, and the same amount of normal saline was given in the other 3 groups.Insulin (2 U/kg) was injected subcutaneously in group C and D 10 min before ligation, and the same amount of normal saline was injected subcutaneously in group A and group B. Plasma creatine kinase MB (CK-MB)and troponin I (cTnI) levels were measured in arterial blood after 120 min of reperfusion, and PI3K and Akt expression in myocardial tissue were detected by Western blot. Results Compared with the group A, the plasma levels of cTnI and CK-MB increased and the expressions of PI3K and phosphorylated protein kinase B (p-Akt) in myocardium decreased in the group B (P<0.05). After insulin treatment, the plasma cTnI [(0.89±0.26)μg/L], CK-MB [(9.24±3.16)μg/L] in the myocardial tissue of the group C decreased, while the expression of PI3K (0.341 8±0.03 1) and p-Akt (0.673 1±0.028) in the myocardial tissue increased (P<0.05). After insulin+ Wortmaninn administration, the plasma cTnI [(1.16±0.29)μg/L] and CK-MB [(12.57±3.01)μg/L]

关 键 词：1-磷脂酰肌醇3-激酶 蛋白激酶类 胰岛素 糖尿病 再灌注损伤 大鼠 

分 类 号：R587.2[医药卫生—内分泌] R542.2[医药卫生—内科学]