坎地沙坦对单侧输尿管梗阻大鼠肾间质纤维化及肾脏骨桥蛋白表达的影响

Expression of osteopontin in rat kidney with unilateral ureteral obstruction and the therapeutic effect of candesartan

目的 观察坎地沙坦（CAN）对单侧输尿管梗阻（UUO）大鼠肾间质纤维化的影响,并观察骨桥蛋白（OPN）与肾间质纤维化的关系及CAN干预对肾脏OPN表达的影响,探讨其在纤维化中的作用机制.方法 （1）36只成年雄性SD大鼠随机分为3组,每组12只：假手术组（Sham）、UUO模型组（UUO）、坎地沙坦治疗组（CAN）.UUO模型组和CAN组大鼠行左侧输尿管结扎术,Sham组只游离左侧输尿管但不结扎.CAN组于术前1 d开始用CAN治疗[10 mg/（kg·d）]灌胃.术后第7、14天分别处死大鼠,左侧肾脏组织行Masson染色,免疫组织化学方法检测肾组织中OPN的表达,逆转录-聚合酶链反应（RT-PCR）检测OPN mRNA表达水平.结果 Masson染色结果显示术后7 d和14 d UUO组大鼠肾纤维化阳性面积分别为15.2%和24.8%,CAN组为1O.1%和18.5%.CAN组与UUO组大鼠术后7 d和14 d大鼠肾纤维化阳性面积差异有统计学意义（P＜0.05）.UUO模型大鼠OPN蛋白及mRNA水平均较Sham组明显升高（P＜0.01）,CAN组OPN蛋白及mRNA水平较UUO组明显降低（P＜0.05）,但较Sham组高（P＜0.01）.结论 CAN能有效地延缓UUO大鼠肾间质纤维化的进展,其延缓肾间质纤维化作用可能与下调OPN蛋白和mRNA有关.

Objective To explore the effect of osteopontin in the renal tubule on the process of renal interstitial fibrosis caused by unilateral ureteral obstruction （UUO） in rats, to examine the expression changes of osteopontin after candesartan intervention and to interpret the anti-fibrotic mechanism. Methods UUO model was established by ligating left ureter. Thirty-six healthy male Sprague-Dawley rats were randomly divided into three groups： sham operation group, UUO group and candesartant reated group. The rats in candesartant reated group were administered with candesartan （ 10 mg/kg every day）, while those in UUO group and sham operation group with saline 10 ml/（kg·day）. The rats were sacrificed at the 7th and 14th day after the surgery. The paraffin-embedded sections of the left kidney were stained with Masson Trichrome staining. The expression of osteopontin mRNA and protein was detected by reverse transcriptionpolymerase chain reaction （RT-PCR） and immunohistochemistry, respectively. Results At the 7th and 14th day after the surgery, the percentage of green-stained region in sections of the left kidney by Masson Trichrome staining was 15.2% and 24. 8% in UUO group, and 10. 1% and 18.5% in candesartan-treated group, respectively. The expression levels of osteopontin mRNA and protein were higher in UUO group than in the sham-operated group （P〈0. 01 ）. As compared with UUO group, candesartan-treated group showed the significant attenuation of osteopontin in the left kidney, which was accompanied with the amelioration of renal interstitial fibrosis process （ P 〈 0. 05 ）. Conclusion Osteopontin participated in the renal interstitial fibrosis. The effect of candesartan on reduction of the expression of osteopontin may be one of the strategies preventing renal interstitial fibrosis.