淫羊藿苷对肺动脉高压模型大鼠部分血管活性物质的影响

Effects of Icariin on Partial Vasoactive Substances in Monocrotaline-induced Pulmonary Arterial Hypertension Rat Model

目的探讨淫羊藿苷(ICA)对野百合碱(MCT)诱导的的肺动脉高压(PAH)大鼠模型部分血管活性物质的影响,以进一步明确ICA抗PAH的作用机制。方法将60只雄性SD大鼠随机分为正常对照组、模型对照组和ICA小、中、大(20,40,80 mg·kg^(-1)·d^(-1))剂量组,每组12只。除正常对照组外,其他组大鼠皮下注射MCT(50 mg·kg^(-1)·d^(-1))复制PAH模型,1周后按分组灌胃给药,连续3周。导管法测定平均肺动脉压(mPAP),分离右心室并称质量,计算右心室肥厚指数(RVHI),苏木精-伊红(HE)染色观察肺小动脉病理改变并计算血管壁面积占血管截面积的百分比。酶联免疫吸附测定(ELISA)法检测血清血管紧张素Ⅱ(AngⅡ)、内皮素(ET)、前列腺素F_(2α)(PGF_(2α))、血栓素(TXA_2)和前列环素(PGI_2)含量。Real time RT-PCR检测肺组织中血管紧张素转化酶(ACE)、环氧化酶2(COX-2)和TXA2合酶(TXAS)mRNA表达的变化。Western blotting检测肺组织中ACE、COX-2和TXAS蛋白含量。结果与正常对照组相比,模型对照组大鼠mPAP[(48.5±5.2)mm Hg]和RVHI(33.3±3.8)%显著增高,肺小动脉管壁增厚,管腔狭窄,重构明显。血清中AngⅡ、PGF2α和TXA_2含量显著增高,ET和PGI_2未见明显改变。ACE、COX-2和TXAS基因表达上调。经ICA(20,40,80 mg·kg^(-1)·d^(-1))处理后,mPAP、RVHI和肺小动脉重构均有改善,其中ICA(40,80 mg·kg^(-1)·d^(-1))改善显著。ICA可抑制ACE、COX-2和TXAS基因表达,降低血清AngⅡ、ET、PGF_(2α)、TXA_2和PGI_2含量。结论 ICA可降低PAH模型大鼠血清中AngⅡ、ET、PGI_2、TXA_2和PGF_(2α)的含量,可能是ICA抗PAH的机制之一。

Objective To investigate the effects of icariin （ICA） on partial vasoactive substances in monocrotaline （MCT）-induced pulmonary arterial hypertension （PAH） rat model. Methods Sixty male SD rats were randomly divided into five groups：normal control group,model control group,ICA low-,middle- and high-dose（20,40,80 mg·kg-1·d-1） group, 12 rats in each group.Except for normal control group, the rats were injected with MCT （50 mg·kg-1·d-1） to establish PAH model.After 1 week MCT-injection,ICA was given by intragastric administration for 3 weeks according to different groups.Mean pulmonary arteiy pressure （mPAP） was recorded through catheter connected with Power Lab system.Except for normal control group, the right ventricular hypertrophy index （ RVHI） was calculated using for^nula ： right ventricle weight/the weight of left ventricle with septumx100%.The morphology of lung artery was assessed by HE staining. Concentration of angiotensin n （ Ang n）,endothelin （ET）,prostaglandine F2 a（PGF2 a ） , thromboxane A2（TXA. ）and prostacyclin （ PGI2） in serum was measured by ELISA kit assay.The protein levels of angiotensin converting enzyme （ACE）,cyclooxygenase-2 （COX-2） and thromboxane A2 synthetase （TXAS） were analyzed by Western blotting,expression of ACE,COX-2 and TXAS mRNA was measured by real time RT-PCR. Results Compared with the normal control group,mPAP [ （4 8 .5 ± 5 .2 ） mmHg] and RVHI （3 3 .3 ± 3 .8 ）%in model control group were significantly increased （ P 〈 0 .0 5 ） , the morphology revealed there was obvious artery remodeling at distal arter, the contents of Ang n , PGF2a ,TXA2 in serum were elevated, and ACE, COX-2 and TXAS gene expression was up-regulated in rats treated with MCT.ICA （40,80 mg·kg-1·d-1） treatment significantly attenuated mPAP,RVHI and pulmonary artery remodeling （P〈0.05）,and decreased the contents of serum AngniETGFiTXAgtand PGI2,a n d inhibited the gene expression of ACE,COX-2 and TXAS. Conclusion ICA decreases the contents of AngII, ET, PGI2, PGF2a and TXA2 in the serum of MCT-induced PAH rats,which may be one of the mechanisms underlying ICA inhibiting PAH.