ACE2在早期糖尿病大鼠肾脏的表达及意义

目的观察早期糖尿病大鼠肾脏血管紧张素转化酶2（ACF2）的表达改变。方法链脲佐菌素（STZ）注射建立1型糖尿病大鼠模型,正常对照组和糖尿病组各6只动物,于建模后0、2、4、6和8周测尾动脉压、尿白蛋白,8周末取血检测胰岛素、血肌酐（SCr）、总胆固醇（TC）、甘油三酯（TG）、血钠和血钾。免疫组织化学染色检测ACE2在肾脏的表达和分布;RT-PCR检测肾脏中ACE2及ACE mRNA表达水平。结果①8周末糖尿病组血压高于正常组（P〈0．05）,2周末始糖尿病组尿蛋白高于正常组（P〈0．05）,8周末糖尿病组TG较正常组明显增高（P〈0．05）,SCr、血钾及血钠无明显差异（P〉（0．05）;②糖尿病组肾小球ACE2蛋白表达低于正常组,而肾小管ACE2显著高于正常组;糖尿病组ACE mRNA高于正常组（P〈0．05）,而ACE2 mRNA与正常组无明显差异（P〉0．05）。结论ACE2较ACE的相对降低参与早期糖尿病肾脏的进展。

Renal Expression of Angiotensin-eonverting Enzyme 2 in Streptozotocin-induced Early Diabetic Rats

Objective To explore the expression of renal angiotensin-converting enzyme 2（ACE2） in the kidney of streptozotocin-indueed diabetic rats at early stage. Methods Twelve rats were assigned randomly to be administrated intraperitoneally with streptozotocin or saline. Blood pressure（BP） and urinary albumin were detected every 2 weeks. Biochemical index of plastma were evaluated at the end of 8 weeks. Pro rein and transcript expression of ACE2 was assessed by immunohistochemistry and reverse transcription poly merase chain reaction（RT-PCR） respectively in kidney. Results Blood pressure elevated modestly in diabetic rats compared with normal animals at the end of study. Massive albuminuia in diabetic rats was continuously detected after 2 weeks. Serum potassium, sodium and creatinine were comparable in two groups. Expression of ACE2 protein in diabetic rats reduced in the glomeruli and up-regulated in the tubules. However, expression of ACE2 mRNA in the whole kidney in diabetic rats remained stable. Conversely, ACEmRNA expression obviously increased. Conclusions The conversed ratio of ACE2 to ACE expression in kidney is involved in pathogenesis of early diabetic nephropathy.