高尿酸血症对血管钙化作用机制的实验性研究

Effect and mechanism of hyperuricemia on vascular calcification in model of rats

目的观察高尿酸血症对大鼠血管钙化的影响。方法实验动物(大鼠28只)随机分正常组、高尿酸血症组、钙化组和钙化+高尿酸血症组,每组7只,钙化组采用维生素D3(300 000 U/kg,1次,肌肉注射)和尼古丁(25 mg/kg溶于花生油中早、晚各灌胃1次)建立大鼠血管钙化模型,高尿酸组采用2%氧嗪酸钾饲料喂养诱导高尿酸血症模型,分别用苦味酸法和尿酸氧化酶过氧化物酶法检测大鼠血清尿酸和肌酐浓度,用Von Kossa染色检测血管钙化程度,用钙离子测试盒、碱性磷酸酶(ALP)试剂盒测定大鼠主动脉钙含量和ALP活性,用硝酸还原酶法检测大鼠血浆NO含量。结果维生素D3和尼古丁能够诱导典型大鼠血管钙化模型,2%氧嗪酸钾饲料喂养可诱导高尿酸血症模型,Von Kossa染色示钙化组主动脉有大量黑色颗粒沉淀,并且血管钙含量、ALP活性明显高于正常组,钙化组+高尿酸血症组钙化最为明显;三组实验组大鼠血浆NO的表达较正常组明显下调。结论高尿酸血症促进大鼠血管钙化,可能与下调NO的表达和上调ALP活性有关。

Objective To observe the effect of hyperuricemia in vascular calcification model of rats. Methods Rats （n=28） were randomly divided into normal,hyperuricemia,calcification and calcification plus hyperuricemia groups （n=7,for each group）. Calcification group was induced by a single dose intramuscular injection of vitamin D3 （300 000 U/kg）plus nicotine （25 mg/kg dissolved in peanut oil） gavage in the morning and evening. Hyperuricemia group was induced by 2% oteracil potassium feed. The concentration of uric acid and creatinine in serum were detected by picric acid method and uric acid enzyme peroxidase respectively. Vascular calcification was determined by Von Kossa staining,calcium content and alkaline phosphatase （ALP） activity were detected by using calcium assay kit and alkaline phosphatase detection kit respectively,and NO content in the plasma was detected by nitrate reductase assay. Results Typical vascular calcification model of rats were induced by vitamin D3 and nicotine,and the hyperuricemia model of rats were induced by 2% oxygen potassium feed too. Von Kossa staining showed that mass black granule deposited in aorta of calcification model of rats,calcium content and alkaline phosphatase （ALP） activity in calcified group were increased significantly than those in the normal group,and the degree of calcificati0n in calcification plus hyperuricemia groups was the most obvious, and the expression of NO in plasma of the three groups was down-regulated significantly compared with those in the normal group. Conclusion Hyperuricemia promotes vascular calcification in rats,which may be related to the down-regulation of NO expression and up-regulation of ALP activity.