中文摘要：

经典瞬时感受器电位通道6（transient receptor potential channel6,TRPC6）蛋白是受体操纵性Ca^2＋通道（ROCC）的分子基础。本文旨在研究TRPC6/ROCC在野百合碱（monocrotaline,MCT）诱发的肺动脉高压大鼠模型中的作用。Sprague-Dawley大鼠随机分为正常对照组（CON组）和MCT组,CON组正常饲养三周,而MCT组按60mg/kg剂量一次性腹腔注射2%MCT,建立MCT诱导的慢性肺动脉高压大鼠模型。通过测定右心室收缩压（RVSP）和右心室重量指数（RVMI）、HE染色观察肺动脉血管形态,分析肺动脉结构重建。半定量RT-PCR和Western blot检测大鼠肺动脉TRPC6 mRNA和蛋白表达水平。血管张力实验中用可特异性激活ROCC、可透膜的DAG拟似物1-oleoyl-2-acetyl-sn-glycerol（OAG）检测大鼠离体肺动脉环的收缩效应。用荧光探针Fluo3-AM测定OAG诱导大鼠肺动脉平滑肌细胞（PASMCs）胞浆游离Ca^2＋浓度（[Ca^2＋]i）。结果显示,与CON组相比,MCT组的RVSP、RVMI均明显增高（P〈0.01）;形态学观察可见肺小动脉平滑肌层明显增厚,管腔减小;TRPC6的mRNA和蛋白质表达无明显变化。在CON组,OAG几乎不引起肺动脉环收缩,而在MCT组,肺动脉环的收缩反应显著增强,差别有显著性意义（P〈0.01）。相比较于CON组,MCT也可使OAG触发的PASMCs[Ca^2＋]i增量值显著升高（P〈0.05）。上述结果提示,MCT预处理对肺动脉TRPC6mRNA和蛋白质水平的表达无显著增强效应,但可促进TRPC6/ROCC介导的PASMCsCa^2＋内流和肺动脉张力升高,诱导大鼠产生肺动脉高压,并进一步诱发肺血管及右心室重构。

英文摘要：

Pulmonary arterial hypertension is associated with profound vascular remodeling and alterations in Ca^2＋ homeostasis in pulmonary arterial smooth muscle cells （PASMCs）.Recent studies show that canonical transient receptor potential channel 6 （TRPC6） genes,which encode receptor-operated cation channels （ROCC） in PASMCs,play an important role in Ca^2＋ regulation and cell proliferation.The aim of the present study was to investigate the role of TRPC6 in monocrotaline （MCT）-induced pulmonary artery hypertension.Sprague-Dawley rats were randomly divided into normal control group and MCT group.In MCT group,pulmonary arterial hypertension was induced by a single intraperitoneal injection of MCT at a dose of 60 mg/kg.After 3 weeks,the right ventricular systolic pressure （RVSP） and the right ventricular mass index （RVMI） were measured.The lung sections were stained by HE and observed under light microscope.Semi-quantitative reverse transcription polymerase chain reaction （RT-PCR） and Western blot were performed to detect the expression of TRPC6 in rat pulmonary arteries.The 1-oleoyl-2-acetyl-sn-glycerol （OAG）-induced contractile tension of pulmonary arteries were measured by vascular ring tension analysis and the intracellular Ca^2＋ concentration （[Ca^2＋]i）of PASMCs was monitored using Fluo3-AM assay.The results showed that RVSP and RVMI markedly elevated in MCT group （P〈0.01） in comparison to CON group.The thickness of pulmonary vascular smooth muscles was increased and the inner diameter of pulmonary arteries was diminished in MCT group.Though there was no significant difference in the levels of mRNA and protein of TRPC6 between CON and MCT groups,the application of OAG,which can directly activate ROCC,induced greater contraction tension of pulmonary arteries （P〈0.01） and more Ca^2＋ entries in PASMCs （P〈0.05） in MCT group compared to those in control group.These results indicate that MCT induces pulmonary artery hypertension and thus remodeling of the right