Angiopoietin-1在糖尿病鼠肾脏中的表达及意义

目的 探讨促血管生成素-1(angiopoietin-1,Ang-1)在糖尿病鼠肾脏中的表达变化及其意义.方法 将SD大鼠随机分为正常对照组(n=42)和模型组(n=42),建立链尿佐菌素(STZ)诱导的糖尿病肾病模型,采用RT-PCR和免疫组化方法,连续多时点观察2组大鼠肾脏Ang-1 mRNA和蛋白表达变化,分析与肾重/体重、尿蛋白、肾小球体积和面积的相关性.结果 糖尿病组4和8周时肾脏Ang-1 mRNA表达上调(P＜0.05),24周时低于对照组(P＜0.05);免疫组化显示Ang-1主要表达于肾小球,糖尿病组4～24周肾小球Ang-1表达均高于对照组(P＜0.05),峰值在4～8周,12周后逐渐下调;Ang-1表达变化与肾重/体重、尿蛋白、肾小球体积和面积呈正相关(r=0.477;r=0.164;r=0.175).结论 糖尿病肾脏存在Ang-1异常改变,表现为早期表达上调,后期表达下调,Ang-1的改变参与了糖尿病肾脏血管结构变化.

The Expression and Significance of the Angiopoietin-1 in the Kidney of Diabetic Rats

Objective To explore the expression and significance of angiopoietin-1(Ang-1) in the renal tissue of diabetic rats.Methodes The SD rats were divided into the diabetic and control groups.The diabetic group was treated by streptozotocin.The expression of Ang-1 in renal tissue was detected by RT-PCR and immunohisochemistry at 2,4,8,12,16,20 and 24 weeks.The level of Ang-1 was quantified by computer image analysis.The relationship between Ang-1 and the index of renal damage including renal/body weight,urinary protein excretion,glomerular volume,and glomerular area was analyzed.Results Ang-1 mRNA in diabetic renal tissue was significantly upregulated at 4 and 8 weeks,compared with diabetic group at other time points or control group at the same time points,and then downregulated gradually after 12 weeks.The level of Ang-1 mRNA decreased significantly as compared with control group at 24 week.Ang-1 was outstandingly expressed in glomeruli.From 4-week to 24-week,the number of Ang-1 staining in diabetic glomeruli increased significantly as compared with control group,being maximal at 4 and 8 weeks,and subsequently decreased after 12 week.Ang-1 level was correlated with renal/body weight,glomerular volume,glomerular area,and urine protein excretion,respectively.Conclusion The change of Ang-1,which is early upregulation and late downregulation,exists in diabetic renal tissue.The unusual expression of Ang-1 is partly connected with the renal changes of diabetic rats.