Rho激酶在肺动脉高压大鼠肺组织中的表达

Expression of Rho kinase in lung tissues of rats with pulmonary hypertension

目的探讨Rho激酶在肺动脉高压大鼠肺组织中的表达及其作用机制。方法48只雄性SD大鼠,随机分为对照组和模型组,测大鼠平均肺动脉压力(mPAP)、右心室肥厚指数(RVHI)。采用RT-PCR及Western blot法,从基因和蛋白水平观察肺组织Rho激酶表达;Western blot法检测其底物肌球蛋白磷酸酶的磷酸化状态,作为该激酶功能活化标志。结果Rho激酶mRNA和蛋白在肺动脉高压早期即明显上调,后期仍维持于较高水平;肌球蛋白磷酸酶磷酸化水平也较对照组显著增高(P均<0.01),并与mPAP及RVHI均呈显著正相关(P均<0.01)。结论肺动脉高压大鼠肺组织中存在Rho激酶的表达上调与功能活化,提示Rho激酶在肺动脉高压发病机制中具有重要作用。

Objective To observe the expression of Rho kinase and its functional activation in lung tissues of rats with pulmonary hypertension,and to investigate its role in the progression of pulmonary hypertension.Methods 48 male Spraque-Dawley rats were randomly divided into control group（24） and model group（24）.The mean pulmonary arterial pressure（mPAP） and right ventricle hypertrophy index（RVHI） were measured.The expressions of Rho kinase gene and protein were examined by semi-quantitative reverse transcription and polymerase chain reaction（RT-PCR） and Western blot,respectively.The phosphorylation of MBS（binding subunit of myosin phosphatase）,a substrate of Rho kinase was detected by Western blot,and defined as the marker of functional activation of the kinase.Results The expressions of Rho kinase mRNA and protein in model group were markedly upregulated even before the onset of pulmonary hypertension（the 3rd day after the experiment） and remained at the high level.The phosphorylation of MBS was significantly higher in the model group than that in the control group,and it was positive correlated with the mPAP and RVHI（all P〈0.01）.Conclusion The Expression and functional activation of Rho kinase increase in lung tissues of pulmonary hypertension rats,suggesting it may play an important role in the pathogenesis of pulmonary hypertension.