脂联素在慢性压力负荷性心力衰竭大鼠心肌中的表达

目的：探讨脂联素（adiponectin）蛋白在慢性心力衰竭尤其是伴有2型糖尿病的大鼠心肌组织中的分布及表达,以及糖尿病对心衰大鼠心肌中脂联素表达的影响.方法：选取Sprague-Dawley雄性大鼠,将其随机分为假手术组（SHAM组）、单纯2型糖尿病组（DM组）、单纯心力衰竭组（HFNDM组）和心力衰竭伴2型糖尿病组（HFDM组）.建立慢性压力负荷性心力衰竭的大鼠模型及高脂高糖饮食后小剂量链脲佐菌素（STZ）诱导的2型糖尿病大鼠模型.运用苏木素-伊红（HE）染色观察大鼠的心脏组织学形态.通过免疫组化、Western Blot定位、定量研究脂联素在心肌中的表达. 结果：大鼠模型建立8周后,DM组及HFDM组大鼠体质量明显低于SHAM组（均P＜0.01）.HFNDM组、DM组及HFDM组的心脏重量指数均显著增加（P＜0.01）.HE染色显示心力衰竭大鼠心肌细胞肥大、排列不整齐、细胞间连接松散,心肌纤维紊乱.免疫组化结果表明各组大鼠心肌中均有脂联素蛋白的表达,定位于细胞浆.Western Blot显示脂联素在糖尿病心肌中低表达（P＜0.05）,心力衰竭心肌中高表达（P＜0.01）. 结论：尽管糖尿病会影响脂联素在大鼠心肌组织中的表达,但在心衰伴糖尿病时心肌中脂联素的表达量仍高于正常大鼠.

Expression of adiponectin in myocardium of rats with chronic pressure overload heart failure

dObjective： To research the distribution and expression levels of adiponectin in myocardium of chronic heart failure （HF） rats, especially those complicated with type 2 diabetes mellitus （DM）, and to investigate the impact of DM on the expression of adiponectin in myocardium of rats with HF. Methods： Male Sprague-Dawley rats were randomly divided into four groups： sham group, DM group, HF group （HFNDM） and HF with DM group （HFDM）. HF model was induced by pressure overload, and DM model was produced by intra-peritoneal injection of low dose of streptozotocin （STZ） after high glucose and fat diet. The general situation of rats was examined. Hematioxylin and eosin （HE） staining was performed to observe the rat hearts histologically. Locational and qualitative analysis of adiponectin in myocardium of rats were assessed by immunohistochemistry and Western blot. Results：8 weeks after rat models established, compared with sham group, the body weight of rats in DM and HFDM groups were significantly decreased（P〈0.01）. Heart weight index of HFNDM, DM and HFDM groups increased significantly compared with sham group （P〈0.01）. HE staining showed that the myocardial cells of HF rats were hypertrophy, irregularly arranged and loosely connected, and myocardial fibers arranged disorderly. Immunohistochemistry showed that adiponectin existed in all groups, and localized in the cytoplasm. Western blot showed low expression of adiponectin in myocardium of DM rats（P〈0. 05）, and high expression in HF rats（P〈0. 01）. Conclusion： The expression of adiponectin is still increased in the myocardium of HF rats with DM, although DM affects its expression.