肾动脉钙化增加2型糖尿病肾病大鼠进行性肾功能损伤

目的探讨肾动脉钙化对2型糖尿病肾病大鼠肾功能的影响。方法将大鼠随机分为对照组(CON组)、糖尿病肾病组(DN组)及DN合并肾动脉血管钙化组(DN+VC组)。DN组和DN+VC组大鼠在高脂高糖饮食基础上腹腔注射链脲菌素(STZ)制备2型糖尿病肾病(diabetic nephropathy,DN)大鼠模型,造模成功后DN+VC组肌注维生素D3及尼古丁灌胃,分别于实验第8、12和16周末处死大鼠,用Von Kossa染色观察大鼠肾动脉钙盐沉积,Ca2+试剂盒检测肾动脉钙含量,免疫荧光双染观察肾动脉α-SMA/BMP2表达,荧光定量PCR检测肾动脉BMP2 mRNA水平等判断肾动脉钙化程度。检测大鼠血清尿素氮、肌酐、胱抑素C及24 h尿蛋白水平,HE染色观察肾组织病理改变。结果 DN组及DN+VC组肾动脉的钙盐沉积及钙含量、BMP2蛋白及基因表达均较同时间点CON组明显增加,DN+VC组较DN组增加更明显(P0.05)。DN组和DN+VC组大鼠血清尿素氮、肌酐、胱抑素C及24 h尿蛋白随时间进展逐渐升高,且明显高于同时间点CON组(P0.05)。与DN组相比,DN+VC组大鼠仅胱抑素C水平明显升高(P0.05),24 h尿蛋白量在第16周时明显增加(P0.05)。DN组大鼠肾组织病理损伤呈进行性加重,DN+VC组大鼠的病理改变较DN组明显加重。肾动脉钙含量与血清尿素氮、肌酐、胱抑素C、24 h尿蛋白以及BMP2 mRNA呈正相关(P0.01)。结论肾动脉钙化的发生及严重程度可能参与和促进糖尿病肾病的进展。

Renal artery calcification increases the progressive renal damage of type 2 diabetic nephropathy rats

Objective To explore the effects of renal artery calcification on the renal function in type 2 diabetic ne-phropathy rats .Methods Rats were randomly divided into control group ( CON group ) , diabetic nephropathy group ( DN group) and DN with vascular calcification group ( DN+VC group) .Rats of group DN and DN +VC were fed with high sugar and fat diet and injected with streptozotocin (STZ)into abdominal cavity to induce type 2 diabetes. After diabetic models were made , rats of group DN+VC were treated by vitamin D 3 plus nicotine .The rats were sacrificed at 8 , 12 and16 week respectively and the pathologic change to the renal artery were microscoped by von Kossa staining .The calcium content were detected by calcium assay kit and double immunofluorescence staining and real-time polymerase chain reaction ( RT-qPCR) were applied to detect the protein and gene expression levels of BMP2 in the renal artery.Measure the levels of blood urea nitrogen (BUN),serum creatinine (Scr),cystatin C (Cys C) and 24 hour urinary protein (24-h UA)respectively at the 8th,12th and 16th weeks.Histopathology of kidney was assessed by hematoxylin/eosin staining .Results The deposition of black granules , the calcium content and the protein and gene expression levels of BMP 2 in DN group were significantly higher than those in group CON and lower than DN+VC group at each time points(P<0.05).The BUN, Scr, Cys C and 24-h UA in group DN and group DN+VC were gradually increased in 8th,12th and 16th weeks, and were higher than those in group CON( P<0.05 ) .Compared with the DN group , only the level of Cys C at each time point and the level of 24-h UA in 16th week in DN+VC group were significantly higher ( P<0.05 ) .The pathological damages of the kidney in group DN showed a continual worsening trend and the pathological changes of the kidney in group DN +VC were more serious than group DN .Calcium content was positively correlated with the increased serum BUN , Scr, Cys C, 24-h UA and BMP2 mRNA ( all P<0.01 ) .Conclusions The occurrence and severity of renal artery calcification may participate in and promote the progression of DN .