表没食子儿茶素没食子酸酯对大鼠草酸钙肾结石形成的影响及其机制研究

观察表没食子儿茶素没食子酸酯(EGCG)对肾结石的治疗作用及对肾脏的保护作用,并对其可能机制进行探讨.采用乙二醇联合氯化铵灌胃的方法建立大鼠草酸钙肾结石模型,并以EGCG对其进行干预.采集大鼠J血液标本,检测大鼠血肌酐、尿素氮以及血钙等生化指标;收集大鼠尿液标本,观察并比较大鼠24h尿量、尿草酸以及尿钙水平;取大鼠肾脏标本制成组织切片,观察大鼠草酸钙肾结石的病理变化.采用实时定量PCR及Western blot对肾组织中骨桥蛋白(OPN)的表达水平进行检测.结果发现,与正常组大鼠相比,结石组大鼠血肌酐、尿素氮、尿钙、尿草酸水平以及肾组织内OPN表达水平均显著升高(P＜0.05),而24h尿量则显著降低(P＜0.05);与肾结石组大鼠相比,在EGCG处理后,大鼠血肌酐、尿素氮、尿钙以及尿草酸水平显著降低(P＜0.05),同时24h尿量显著升高(P＜0.05),呈浓度依赖性.与对照组相比,肾结石组大鼠肾组织草酸钙结石病理改变明显,而在EGCG处理后,大鼠肾脏病理改变明显改善,呈浓度依赖性.此外,EGCG处理后大鼠肾脏OPN表达水平显著降低,也呈浓度依赖性.结果可推知EGCG能够抑制大鼠肾脏内草酸钙肾结石的形成,并对肾功能有明显的保护作用.

Study on inhibitory effect of EGCG on Calcium oxalate nephrolithiasis in rats and its related mechanism

In the study, the inhibitory effect of epigallocatechin gallate (EGCG) on Calcium oxalate nephrolithiasis and its possible mechanism were investigated. The rat Calcium oxalate nephrolithiasis model was induced through the combined oral administration of ethylene glycol and ammonium chloride, which was intervened with EGCG. Rat blood samples were collected to detect blood creatinine (Cr), blood urea nitrogen (BUN) and blood calcium. Rat urine samples were collected to observe and compare 24-hour urine volume, oxalic acid (Ox) and calcium in urine. Renal samples were collected to prepare tissue slices and observe the pathological changes in Calcium oxalate nephrolithiasis. The expression of osteopontin (OPN) in renal tissues was evaluated by Real-time PCR and Western blot. According to the results, compared with normal rats, rats in the nephrolithiasis model showed significant increases in Cr, BUN, urine Calcium, urine Ox and renal OPN expression (P<0.05), but obvious decrease in 24-hour urine volume (P<0.05);Compared with rats with nephrolithiasis, those processed with EGCG revealed remarkable declines in Cr, BUN, urine Calcium and urine Ox (P<0.05), with significant rise in 24-hour urine volume (P<0.05) in a concentration-dependent manner. Additionally, compared with the control group, nephrolithiasis rats showed significant pathological changes in Calcium oxalate calculus. After EGCG treatment, the renal pathological changes and OPN expression attenuated significantly in a concentration-dependent manner. The results showed that EGCG inhibits the formation of calcium oxalate nephrolithiasis in rats and shows a notable protective effect on renal functions.