目的　该研究通过阿霉素肾病大鼠模型 ,动态观察α骨化醇 (αD3)对肾组织肾母细胞瘤抑制基因(WT1 )表达及其对肾病大鼠蛋白尿的影响。方法　 12 0只SD雄性大鼠随机分为对照组、肾病组、激素组、αD3组和联合组 (激素 +αD3) ,每组 2 4只。一次性尾静脉注射阿霉素制备阿霉素肾病模型 ,对照组一次性尾静脉注射同体积生理盐水。模型制备 2周后 ,激素组、αD3组和联合组分别每天灌服泼尼松、αD3及泼尼松与αD3,共 4周。对照组和肾病组分别灌服等量蒸馏水。于实验第 2 ,4 ,6周末各组随机抽取 8只大鼠 ,收集 2 4h尿标本后处死大鼠 ,分离肾组织 ,观察肾组织病变。用考马斯亮蓝法检测 2 4h尿蛋白含量 ,用间接免疫荧光法检测肾组织WT1 的表达。结果　第 2周末 ,肾病组、激素组、αD3组及联合组大鼠 2 4h尿蛋白含量高于对照组 ,差异有显著性意义 (P <0 .0 1) ,第 4周及第 6周末 ,肾病组大鼠尿蛋白逐渐上升 ,激素组、αD3组及联合组尿蛋白降低 ,均低于同时间点肾病组 ,差异有显著性意义 (P <0 .0 1) ;WT1 表达仅见于肾小球 ,肾小管几乎无表达。第 2周末 ,肾病组、激素组、αD3组及联合组大鼠WT1 表达明显低于对照组 (P <0 .0 1) ;第 4及第 6周末 ,肾病组WT1 表达进一步减弱 ,激素组、αD3组及联合组WT1 的表达增加

Objective This paper aims at studying the effects of alphacalcidol (αD 3) on Wilms' tumor 1 gene (WT 1) expression of renal tissues and on proteinuria in rats with nephrotic syndrome so as to understand the mechanism of proteinuria occurrence. Methods One hundred and twenty SD rats were randomly assigned into five groups: a Control group, a Nephropathy group, a Prednisone-treated nephropathy group (Prednisone group), a αD 3-treated nephropathy group (αD 3 group) and a Prednisone and αD 3-treated group (Combination group). Nephrotic syndrome rat models were established by an injection of adriamycin via the tail vein. The Control group received an injection of 0.1 ml normal saline. After 2 weeks of injections, different treatments were given for the 5 groups daily for 4 weeks. The Prednisone group was administered prednisone daily (12 mg/kg); the αD 3 group was administered αD 3 daily ( 0.03 μg/kg); and the Combination group was administered prednisone (12 mg/kg) and αD 3 ( 0.03 μg/kg) daily. The Control group and the Nephropathy group were given distilled water with the same volume as the 3 treatment groups. Every 2 weeks specimens of the urine of 8 rats in each group were collected for 24 hrs in order to detect the 24-hr urinary protein content, and then the rats were sacrificed for histological study. Immunofluorescence was used to detect the WT 1 expression of renal tissues. Results By the 2nd week, the 24-hr urinary protein contents of the Nephropathy group, the Prednisone group, the αD 3 group and the Combination group were significantly higher than that of the Control group (P< 0.01). By the 4th and 6th weeks, the 24-hr urinary protein contents increased in the Nephropathy group, while those of the Prednisone group, the αD 3 group and the Combination group gradually decreased compared with those of the 2nd week. There were significant differences between the Nephropathy group and the 3 treated-nephropathy groups (P< 0.01). By the 2nd week, the WT 1 expressions of the Nephropathy group, the Prednisone group, the αD 3 group and the Combination group were significantly lower that of the Control group (P< 0.01), while the pathologic scores of the 4 nephropathy groups were significantly higher that of the Control group (P< 0.01). By the 4th and 6th weeks, the WT 1 expression in the Nephropathy group decreased, while those of the 3 treated-nephropathy groups elevated compared with those of the 2nd week. Significant differences were found between the Nephropathy group and the 3 treated- nephropathy groups. The WT 1 expression was negatively correlated to the 24-hr urinary protein content (P< 0.01). By the 4th week, the pathologic scores of the Prednisone group, the αD 3 group and the Combination group rose compared with those of the 2nd week, but they decreased by the 6th week. The pathologic scores of the αD 3 group by the 4th and 6th weeks were lower than that of the Nephropathy group (P< 0.01). Conclusions αD 3 may have protective effects against nephrotic syndrome by increasing the WT 1 expression and decreasing the drainage of proteinuria.