二甲双胍对糖尿病大鼠心肌纤维化的影响

目的 探讨二甲双胍对糖尿病大鼠心肌纤维化的作用。方法 雄性SD大鼠随机分为正常对照组(NC组，n=8、糖尿病组(DM组，n=9)、二甲双胍组(MET组，n=10)。DM组、MET组大鼠高脂饲料喂养4周，腹腔注射小剂量链脲佐菌素(STZ)建立糖尿病模型，DM组、MET组大鼠继续高脂饲料喂养，并且MET组大鼠给予二甲双胍500mg/(kg·d)灌胃6周。实验末，计算心脏体质量比(HW/BW)，采用Masson染色及免疫组织化学染色，检测左室心肌胶原含量及转化生长因子-β1(TGF β1)、血小板反应蛋白-1(TSP-1)表达的变化。结果 与NC组相比，DM组和MET组大鼠HW、HW/BW均显著增加(P<0 .05)，心肌胶原含量、TGF-β1、TSP-1表达均显著增加(P<0.05)；与DM组大鼠相比，MET组大鼠HW/BW显著减轻(P<0.05)，心肌胶原含量、TGF-β1、TSP-1表达均显著减少(P<0.05)。结论 糖尿病大鼠存在心肌纤维化，二甲双胍可以减轻糖尿病大鼠的心肌纤维化。

Effect of metformin on myocardial fibrosis in diabetic rats

Objective To observe the effect of metformin on myocardial fibrosis in diabetic rats. Methods Male SD rats were randomly divided into 3 groups: the normal control group(NC group), the diabetes group(DM group), and the diabetes with metformin treatment group(MET group). After SD rats were fed a high fat diet for four weeks, low-doses of streptozotocin(STZ) were intraperitoneally injected to establish the model of diabetes .Then, the DM group and MET group rats were fed the high-fat diet and metformin( ig, 500mg/(kg·d)) was given to the MET group for another 6 weeks . After the last administration, the ratio of heart to body weight (HW / BW) was measured, while myocardial collagen content was quantified through Masson-staining and expressions of TGF-β1 and TSP-1 were detected by immunohistochemical staining. Results Compared with the NC group, the HW / BW and myocardial collagen contents were significantly increased in the DM group and MET group(P<0.05), while expressions of TGF-β1 and TSP-1 were also markedly increased in both groups(P<0.05). Compared with the DM group, the HW / BW, myocardial collagen contents and expressions of TGF-β1 and TSP-1 were significantly reduced in the MET group. Conclusion Metformin shows the effect of anti- myocardium fibrosis in diabetic rats.