黄芪当归合剂对单侧输尿管梗阻大鼠肾脏血管活性物质变化的影响

Astragulus & Angelica mixture enhances nitric oxide production and reduces angiotensin II in the kidney of UUO rats

目的本研究通过观察黄芪当归合剂(A&A)对单侧输尿管梗阻(UUO)模型肾组织血管紧张素Ⅱ(Ang-Ⅱ)、内皮素-1(ET-1)、一氧化氮(NO)水平及一氧化氮合酶(NOS)的影响, 以进一步揭示A&A抑制肾纤维化机制。方法 Wistar大鼠随机分为假手术(Sham)、UUO和 UAA(UUO+A&A)组,造模后0、3、7、10 d分析各组肾脏中NO、Ang-Ⅱ、ET-1水平和NOS活性及 3种NOS的表达。结果 (1)造模后UUO组的Ang-Ⅱ和ET-1水平持续增高:A&A仅在第3天时降低Ang-Ⅱ水平(P<0．05)。(2)造模后UUO组的NO浓度在第10天时才明显增高:而UAA 组中NO浓度逐渐增高,第3天时明显高于UUO组(P<0．05)。(3)UUO组内皮型eNOS在髓质血管内表达增高,且UAA组与UUO组间没有显著性差异。第3天时UAA组神经型nNOS表达低于UUO组(P<0．05)。UAA组cNOS的活性明显高于Sham和UUO组。诱导型iNOS表达和活性3组间差异均无统计学意义。结论梗阻性肾病中,A&A在早期降低肾内Ang-Ⅱ水平、且持续增强eNOS活性使NO产生增加,从而可能降低血管张力、改善肾脏的缺血及缺氧状态,减轻肾间质纤维化。

Objective To investigate the therapeutic effects of Astragalus ＆ Angelica （A＆A）, the mixture of Chinese herbs, on different vasoconstrictors and vasodilators in the process of renal interstitial fibrosis in rats with unilateral ureteral obstruction （UUO）. Methods Wistar rats were randomly divided into Sham,UUO and UAA （UUO＋A＆A） groups. After administration of A＆A （14 g·kg^-1·d^-1） for 0, 3, 7 and 10 days, the levels of Ang-Ⅱ , ET-1, nitric oxide（NO） and the activities of different NOS in renal homogenate were measured by RIA or enzyme method. The expression levels of eNOS, nNOS, iNOS were detected in the kidney by immunohistochemistry and semiquantitively assessed by Western blot. Results After A＆A administration, the levels of Ang-Ⅱ and ET-Ⅰ were increased in UUO at all time points （P 〈 0.05）. A＆A suppressed Ang-Ⅱ level only at day 3 （1.12±0.24 vs 1.80±0.19, P 〈 0.05） but not at the other days. It had no any effect on ET-1. On the other hand, NO release was increased at day 7 and day 10 in UUO rats （P 〈 0.05）, but it was elevated earlier at day 3 （P 〈 0.05） and was progressively increased in the following days in UAA group. In further study, the distribution of three isoforms of NOS in the kidney showed no difference between UUO and UAA groups. The activities of constitutive NOS and iNOS remained unchange in UUO group as compared to Sham. In contrast, the activity of constitutive NOS was much higher in UAA as compared to UUO rats, it was un-regulated by 78%, 68% and 78% at day 3, 7 and day 10 respectively, even though the protein expression levels of eNOS, nNOS and iNOS in renal tissue were unaffected in UAA rats. Conclusions The anti-fibrosis effects of A＆A may be associated with improving chronic ischemic status in UUO rats. In the early stage of UUO, A＆A down-regulates Ang-Ⅱ and persistently enhances eNOS activities, which leads to up-regulation of NO production.