达格列净对糖尿病肾病大鼠肾脏保护作用机制研究

目的 探讨达格列净对糖尿病肾病（diabetic nephropathy，DN）大鼠的肾脏保护作用及对AMP活化蛋白激酶（AMP-activated protein kinase，AMPK）/哺乳动物雷帕霉素靶蛋白（mammalian target of rapamycin，mTOR）信号通路表达的影响。方法 SPF级Wistar雄性大鼠40只，随机分为正常组、模型组、低剂量组和高剂量组，每组各10只。成功制备DN模型后，正常组大鼠给予普通饲料+生理盐水灌胃；模型组大鼠给予高糖高脂饲料+生理盐水灌胃；低剂量组大鼠给予高糖高脂饲料+达格列净1mg/（kg·d）灌胃；高剂量组大鼠给予高糖高脂饲料+达格列净10mg/（kg·d）灌胃。各组大鼠连续干预12周。比较各组大鼠的肾功能指标、肾脏病理组织变化、p-AMPK和p-mTOR蛋白表达、Ⅰ型胶原（collagen type Ⅰ，COL Ⅰ）、Ⅳ型胶原（collagen type Ⅳ，COL Ⅳ）、纤维连接蛋白（fibronectin，FN）水平。结果 模型组、低剂量组和高剂量组大鼠的血尿素氮（blood urea nitrogen，BUN）、血肌酐（serum creatinine，SCr）、24h尿蛋白定量、p-mTOR蛋白表达、COL Ⅰ、COL Ⅳ和FN水平均显著高于正常组，p-AMPK蛋白表达显著低于正常组（P<0.05）；低剂量组和高剂量组大鼠的BUN、SCr、24h尿蛋白定量、p-mTOR蛋白表达、COL Ⅰ、COL Ⅳ和FN水平均显著低于模型组，p-AMPK蛋白表达显著高于模型组（P<0.05）；高剂量组大鼠的BUN、SCr、24h尿蛋白定量、p-mTOR蛋白表达、COL Ⅰ、COL Ⅳ和FN水平均显著低于低剂量组，p-AMPK蛋白表达显著高于低剂量组（P<0.05）。结论 达格列净对DN大鼠具有良好的肾脏保护作用，其机制可能与调节AMPK/mTOR信号通路表达有关。

Study on the protective mechanism of dapagliflozin on kidney in diabetic nephropathy rats

Objective To investigate the protective effect of dapagliflozin on kidney and the expression of AMP-activated protein kinase (AMPK)/ mammalian target of rapamycin (mTOR) signaling pathway in diabetic nephropathy (DN) rats. Methods A total of 40 SPF Wistar male rats were randomly divided into normal group, model group, low-dose group and high-dose group, with 10 rats in each group. After the DN model was successfully prepared, the rats in normal group were given normal diet + normal saline by gavage, the rats in model group was given high sugar and high fat feed + normal saline by gavage, the rats in low-dose group was given high sugar and high fat feed+1mg/(kg·d) of dapagliflozin by gavage, the rats in high-dose group was given high sugar and high fat feed+10mg/(kg·d) of dapagliflozin by gavage. Rats in each group were continuously gavaged for 12 weeks. Renal function indexes, renal pathological changes, p-AMPK and p-mTOR protein expression, collagen type Ⅰ (COL Ⅰ), collagen type Ⅳ (COL Ⅳ) and fibronectin (FN) of all groups were compared. Results Blood urea nitrogen (BUN), serum creatinine (SCr), 24h urinary protein quantity, p-mTOR protein expression, COL Ⅰ, COL Ⅳ and FN levels of rats in model group, low-dose group and high-dose group were significantly higher than those in normal group, and p-AMPK protein expression was significantly lower than that of normal group (P<0.05). BUN, SCr, 24h urinary protein quantity, p-mTOR protein expression, COL Ⅰ, COL Ⅳ and FN levels of rats in low-dose group and high-dose group were significantly lower than those in model group, while p-AMPK protein expression was significantly higher than that in model group (P<0.05). BUN, SCr, 24h urinary protein quantity, p-mTOR protein expression, COL Ⅰ, COL Ⅳ and FN levels in high-dose group were significantly lower than those in low-dose group, and p-AMPK protein expression was significantly higher than that in low-dose group (P<0.05). Conclusion Dapagliflozin has a good kidney protection effect on DN rats, and its mechanism may be related to the regulation of AMPK/mTOR signaling pathway.