大鼠心肌梗死致心力衰竭模型不同时期Gα_(11)蛋白的表达

Myocardial expression of Gα_(11) protein at different periods in congestive heart failure rat models

目的 观测心力衰竭不同时期Gα11蛋白表达的改变 ,探讨Gα11蛋白与心室重塑、心肌肥大和心力衰竭的关系。方法 通过结扎雄性SD大鼠左冠状动脉前降支建立实验性心肌肥大的心力衰竭动物模型 ;应用Gα11蛋白单克隆抗体对实验性梗死后心肌组织进行免疫组织化学方法和图像分析技术 ,结合HE染色对Gα11蛋白在心肌细胞肥大不同时期 (3d、1周、2周、3周和 6周 )的表达水平进行观察 ,测定其阳性单位 (PU)。结果 (1)对照组Gα11蛋白保持较稳定的表达水平 ;心力衰竭动物模型术后 3d至 3周Gα11蛋白表达量显著增加 ,3周阶段达高峰 ;3周至 6周Gα11蛋白表达水平逐渐下降 ,并有缺失 ;图像分析也显示在演变过程中 ,Gα11蛋白的阳性面积和强度呈显著的动态变化 ,在1周 [左室心肌梗死面积 (LVMI≥ 2 0 %组 :P <0 .0 5 ) ]、2周 (LVMI≥ 2 0 %组 :P <0 .0 1)、3周 (LVMI≥ 2 0 %组 :P <0 .0 0 0 1)。结论 (1)心肌肥厚时期Gα11蛋白表达增加 ;(2 )心力衰竭时期Gα11蛋白表达较心肌肥大时期下降和有缺失 ;(3)Gα11蛋白在心肌肥大、心室重塑和心力衰竭的发展演变中起重要的介导作用。

Objective To investigate the significance of positive expression of Gα 11 protein at different periods of heart failure and the relationship between that and left ventricular remodeling,myocardial hypertrophy and heart failure.Methods (1) The experiment was performed on myocardial hypertrophy model of Sprague Dawley rats.SD rat left ventricular hypertrophy model was established by ligating the left coronary artery.(2) The myocardial samples from the rats with myocardial hypertrophy and control rats were stained by histochemical,immunohistochemical staining and examined by image analysis with monoclonal antibody of Gα 11 protein.Image analysis was employed to measure the positive unit(PU) of Gα 11 protein.The data were compared with cardiac function.(3) In different periods (third day and first,second,third and sixth weeks) of myocardial hypertrophy,the expression of Gα 11 protein was assessed .Results (1) In control group,the expression of Gα 11 protein in the myocardium always kept stable,while in heart failure model,it obviously increased from third day to third week,reached peak at third week,then decreased progressively from third week to sixth week and depletion also occurred.(2) Image analysis showed that in heart failure model (LVMI≥20%),the intensity and area of Gα 11 protein changed significantly and were much greater than those of control in the stages of first week (P< 0.05)?second week (P<0.01) and third week (P<0.0001).Conclusions (1) In myocardial hypertrophy period,the expression of Gα 11 protein increased in the rats with LVMI≥20%,and reached peak at third week.(2) In heart failure period,the expression of Gα 11 protein decreased progressively in the rats with LVMI≥20%anddepletionalsooccurred .Itdidnotobviouslyincreaseincomparisonwithcontrolatsixthweek .(3)Gα11 proteinmaysignificantlymediatetheevolutionofmyocardialhypertrophy ,ventricularremodelingandheartfail ure .