胰岛素抵抗小鼠心肌脂联素水平与心脏重构的关系

Relationship between Myocardial Adiponectin and Cardiac Remodeling in Insulin Resistant Mice

目的观察胰岛素抵抗小鼠心肌脂联素(adiponectin,APN)水平的变化,探讨心肌APN表达水平对胰岛素抵抗小鼠心脏重构的影响。方法小鼠予以高脂饲料诱导胰岛素抵抗。每周称1次体重。喂养12周后取材,测定空腹血糖、胰岛素水平,计算胰岛素抵抗指数;测定左心室重量,计算左心室重量指数;并使用免疫组化、Western blot法检测心肌APN的表达。结果胰岛素抵抗小鼠空腹血糖(10.49±1.09)较对照组(6.6±0.47)升高,空腹胰岛素(20.32±4.17)较对照组(9.19±4.54)升高、胰岛素抵抗指数(9.56±2.60)较对照组(2.68±1.31)升高,左心室重量指数(3.23±0.28)较对照组(2.65±0.24)升高,免疫组化提示心肌APN表达(0.29±0.02)较对照组(0.37±0.03)下降,Western blot检测亦提示心肌APN蛋白表达(0.77±0.23)较对照组(1.27±0.29)下降(P均<0.01)。左心室重量指数与血糖、胰岛素、胰岛素抵抗指数呈正相关(r=0.640、0.599、0.608,P<0.05),与心肌APN水平呈负相关(r=-0.675,P=0.006)。结论胰岛素抵抗可导致心肌APN水平下降,心肌APN水平下降可能是胰岛素抵抗导致心脏重构的机制之一。

Objective To observe the expression levels of myocardial adiponectin in Insulin resistant mice and to investigate the relationship between myocardial adiponectin and cardiac remodeling in Insulin resistant mice.Methods We selected mice as the research objects and given high-fat feed to induce insulin resistance model.The feed and intervention lasted for 12 weeks. Glucometer was used to detect FPG level and ELISA was used to detect FINS level while HOMA-IR was calculated. The ventriculus sinister of mice was taken to calculate left ventricular weight index（LVWI）. Immunohistochemical method and western blotting method were employed to determine the expression level of myocardial adiponectin. Results The serum level of FPG,FINS,HOMA-IR,LVWI in IR group were significantly higher than those in control group while.the level of myocardial adiponectin in IR group was significantly lower than that in control group. LVWI was significantly positively correlated with FPG,FINS and HOMA-IR（r=0.640,0.599,0.608,P0.05）,and was significantly negatively correlated with the expression level of myocardial adiponectin（r=-0.675,P=0.006）. Conclusion Insulin resistance could decrease the expression level of myocardial adiponectin. Cardiac remodeling caused by Insulin resistant may be correlated with the reduction of myocardial adiponectin.