槲皮素对糖尿病肾病大鼠的肾小球周期素激酶抑制剂P27水平的影响

Influence of quercetin on glomerular cyclin-kinase inhibitor P27 in rats with diabetic glomerulus

目的:探讨槲皮素对糖尿病肾病的影响及该影响与肾小球周期素激酶抑制剂P27的关系。方法:腹腔注射链脲佐菌素建立糖尿病(DM)模型,分别以生理盐水或槲皮素(100 mg·kg1·d-1)灌胃8周。蛋白印迹(Western杂交)法测定肾小球裂解液P27蛋白水平,ELISA法测定肾小球裂解液细胞外基质(ECM)蛋白(Ⅳ型胶原及纤维连接蛋白)和尿白蛋白。结果:DM 8周大鼠肾小球P27水平增高,ECM蛋白水平增加,尿白蛋白排泄增多,肾质量/体质量比值增高。槲皮素灌胃8周显著降低DM大鼠。肾小球P27水平(10.6±3.1 vs 18.5±4.3,P<0.01)和ECM蛋白水平,减少尿白蛋白排泄[(17.62±3.02)vs(39.62±3.68)μg/24 h,P<0.01],降低DM大鼠肾质量/体质量比值(11.35±1.76 vs 14.87±2.02,P<0.01)。槲皮素不改变DM大鼠血糖水平。结论:槲皮素可能通过降低肾小球P27水平改善糖尿病肾病症状。

Objective: To investigate the relationship between the cyclin kinase inhibitor P27 and the protective effect of quercetin on the diabetic glomerulus in rats. Methods:STZ-induced diabetic rats were given quercetin 100 mg·kg-1·d-1 for 8 weeks. The P27 protein in glomerular lysate was detected with Western blot. The extracellular matrix (ECM) protein (type Ⅳcollagen and fibronectin) of glomerular lysate and 24 h urine albumin were examined with ELISA. Results:Glomerular P27 protein and ECM increased in diabetic rats. Meanwhile,the 24 h urine albumin excretion elevated and ratio of kidney mass/ body mass increased in diabetic rats. Quercetin decreased glomerular P27 level (10. 6±3. 1 vs 18. 5±4. 3,P<0. 01), 24 h urine albumin excretion [(17. 62 ? 3. 02) vs (39. 62 ± 3. 68) μg/24 h, P<0. 01], and the ratio of kidney weight over body weight (11. 35±1. 76 vs 14. 87 ? 2. 02,P<0. 01). The blood glucose remained constant in diabetic rats and quercetin-treated diabetic rats. Conclusion: Quercetin may protect diabetic glomerulus through decreasing glomerular P27 level.