大鼠野百合碱肺高压模型基质金属蛋白酶-1、基质金属蛋白酶-9 mRNA的表达

目的 观察基质金属蛋白酶(MMP)-1、-9在大鼠野百合碱肺高压模型中的表达.方法 SD大鼠24只,随机分为野百合碱注射组(MCT)和对照组(Con).MCT组给予野百合碱60 mg/kg单次右侧皮下注射.饲养6周后,采集肺组织样本进行肺小动脉形态学测量,原位杂交和逆转录-聚合酶链反应(RT-PCR)检测.结果 MCT组肺小动脉横断面的厚度指数(TI)及面积指数(AI)的均值都高于Con组(TI:0.41±0.13比0.13 ±0.07,P＜0.05;AI:0.64±0.15比0.23 ±0.11,P＜0.05).MMP-1、-9主要分布于肺小动脉内皮细胞和外膜成纤维细胞,MCT组肺组织中MMP-1、-9mRNA转录水平高于对照组(0.72±0.13比0.28±0.01,P＜0.05;0.85±0.15比0.39±0.12,P＜0.05).结论 MMP-1、-9活性表达的增强,参与了肺高压肺血管重构的机制.     

两种大鼠肺动脉高压模型转化生长因子-β1及其I型受体表达的比较

目的 观察转化生长因子(TGF)-β1及其Ⅰ型受体在两种大鼠肺动脉高压模型中表达的变化.方法 36只Spargue-Dawley大鼠,对照组、分流型和药物型肺动脉高压模型各12只,使用原位杂交方法观察TGF-β1及其Ⅰ型受体在肺小动脉表达的定位,并使用逆转录-聚合酶链反应(RT-PCR)法观察两者mRNA转录量的变化.结果 大鼠分流型与药物型肺动脉高压模型中TGF-β1及其Ⅰ型受体mRNA主要分布于肺小动脉内皮细胞和外膜成纤维细胞,两种模型中TGF-β1(1.17±0.09、1.09±0.07)及其Ⅰ型受体(0.80±0.06、0.93±0.02)mRNA转录均较对照组明显增加,三组间均数比较差异有统计学意义(P0.05).结论 TGF-β1信号参与了肺动脉高压肺血管重塑的过程,但在不同的模型中作用机制不同.     

交感神经递质通过促进肺动脉平滑肌细胞增殖参与野百合碱诱导肺动脉高压模型大鼠的肺血管重塑

目的探讨野百合碱诱导的大鼠肺动脉高压(PAH)模型中肺中小血管周围去甲肾上腺素(NE)和神经肽Y(NPY)的水平及其在肺血管重塑的作用。方法将20只6～8周龄的Sprague Dawley(SD)大鼠(安徽医科大学实验动物中心提供)采用抽签法随机分为对照组(Control组) 9只和野百合碱诱导肺动脉高压组(MCT-PAH组)11只。通过腹腔注射野百合碱(MCT, 50 mg/kg)构建PAH模型。通过血流动力学参数、苏木精-伊红(HE)染色评价PAH模型。酶联免疫吸附试验(ELISA)、免疫荧光及蛋白质印迹法评价NE和NPY表达。提取大鼠肺动脉组织做原代肺动脉平滑肌细胞(PASMCs)培养, 通过细胞计数试剂盒(CCK-8)、流式细胞术检测PASMCs的增殖能力, 两组之间比较采用t检验。结果与Control组比较, HE染色显示MCT-PAH组大鼠右心室心肌排列紊乱, 间隙增宽, 周围可见胶原纤维沉积, 远端肺小动脉呈向心性肥厚, 管壁增厚, 管腔明显变窄;血浆NE[(100.32±8.95) nmol/L比(124.69±20.66) nmol/L, t=-2.892, P<...     

不同数目骨髓间充质干细胞移植对大鼠肺动脉高压的作用及内皮素-1表达的影响

目的探讨不同数目骨髓间充质干细胞(mesenchymal stem cells,MSCs)移植对野百合碱(MCT)诱导大鼠肺动脉高压的治疗作用,以及对内皮素-1(endothelin-1,ET-1)表达的影响。方法成年雄性Wistar大鼠40只(体重180～250 g),按随机数字表法分为4组,每组10只。A组:大鼠腹腔注射MCT 60 mg/kg,经颈外静脉注入1×106MSCs;B组:大鼠腹腔注射MCT 60 mg/kg,经颈外静脉注入5×105MSCs;MCT组:大鼠腹腔注射MCT60 mg/kg和等量磷酸盐缓冲液(PBS);对照组:大鼠腹腔注入等量生理盐水和等量PBS。MSCs移植4周后测定右心室收缩压(RVSP),计算心室比,即右心室/(左心室+室间隔)[RV/(LV+VS)];观察肺组织形态学改变;检测肺组织ET-1基因表达和血清ET-1的含量。结果 MSCs移植4周后,A组RVSP和RV/(LV+VS)与MCT组比较明显降低[(35.8±4.2)mm Hg vs.(47.2±10.1)mm Hg,P<0.01;(0.357±0.032)vs.(0.452±0.056),P<0.01];而B组与MCT组比较差异无统计学意义(P>0.05)。A组肺小动脉中膜厚度较MCT组明显变薄[(19.7%±3.0%)vs.(26.8%±3.6%),P<0.01];而B组则差异无统计学意义。逆转录酶-聚合酶链反应(RTase-PCR)检测结果显示,MCT组肺组织ET-1 mRNA表达最强,A组肺组织ET-1 mRNA与MCT组比较明显减弱,B组表达与MCT组接近。A组血清ET-1含量与MCT组比较明显减少。结论 MSCs静脉移植对MCT诱导的肺动脉高压具有抑制作用,并能减少肺组织ET-1的mRNA表达及血清ET-1浓度。采用1×106MSCs移植具有较好的治疗作用。     

分泌型蛋白质GREM1在体-肺分流性肺动脉高压中的作用

目的探讨骨形态发生蛋白(BMP)拮抗因子GREM1作为先天性心脏病相关肺动脉高压(CHD/PAH)患者BMP信号通路活性下调机制的可能。方法外科手术建立大鼠体-肺分流性PAH模型。术后12周,右心导管及心脏超声测量右心系统血流动力学指标及形态学指标,心、肺、血标本取材。计算右心肥厚指数,评估肺血管重构情况,检测肺组织BMP信号通路相关蛋白及GREM1的表达变化及血浆GREM1浓度。体外培养肺动脉内皮细胞(PAECs),研究GREM1对PAECs增殖及凋亡的影响。结果体-肺分流大鼠模型成功再现了CHD/PAH的PAH状态。在分流性肺组织中,缺氧诱导因子-1α(HIF-1α)表达水平无改变(P>0.05),GREM1表达增加,但BMP信号通路组份的表达下降(P<0.05),而矫正体-肺分流可逆转这一趋势(P<0.05)。免疫组织化学染色显示重构的肺小动脉中GREM1表达增加(P<0.05)。体外细胞实验显示,增殖的PAECs中BMP信号通路相关蛋白下调而GREM1表达和分泌显著升高(P<0.05),且GREM1通过拮抗BMP信号通路显著促进PAECs的增殖并抑制其凋亡(P<0.05)。此外,体-肺分流大鼠的血浆GREM1显著升高且与肺血流动力学参数密切相关(P<0.05)。结论体-肺分流引起肺组织GREM1表达升高,而升高的GREM1通过下调BMP信号通路活性诱导肺血管重构,促进肺动脉高压的形成。此研究结果为CHD/PAH肺组织BMP信号通路活性下调机制提供了一种新的解释。     

骨髓间充质干细胞移植肺动脉高压大鼠内皮素-1的变化

目的 观察骨髓间充质干细胞(MSCs)静脉移植对野百合碱(MCT)诱导肺动脉高压(PAH)大鼠的内皮素-1(ET-1)表达的影响.方法 培养大鼠幼鼠骨髓MSCs,传代纯化,取第3～5代细胞进行移植.Wistar大鼠30只,成组设计(n=10)为3组:实验组、MCT组和对照组.前两组腹腔注射60 mg/kg MCT(对照组注射等量生理盐水)诱导后,实验组颈外静脉注射含1×106 MSCs的磷酸盐缓冲液(PBS),后两组注入等量PBS.4周后检测大鼠右心室收缩压(RVSP);肺组织苏木素-伊红(HE)染色;肺组织分离mRNA,逆转录酶聚合酶链反应(RT-PCR)法检测组织表达前体原ET-1 mRNA的水平;酶联免疫吸附试验(ELISA)法测定血清ET-1的表达.统计数据进行成组t检验.结果 MSCs颈外静脉移植4周后,实验组与MCT组比较RVSP明显下降[(35.6±8.4) mmHg(1 mm Hg =0.133 kPa)比(47.2±10.5) mmHg,P＜0.05];病理染色可见实验组与对照组比较肺小动脉壁明显变薄;肺组织前体原ET-1 mRNA半定量显示实验组较MCT组表达减少(0.251 ±0.048比0.391 ±0.035,P＜0.05),血浆ET-1结果均显示对照组ET-1表达很少(2.23 ±0.43) ng/L,与MCT组比较,MSCs移植降低了ET-1的表达[(4.05±0.82) ng/L比(5.75 ±0.75) ng/L,P＜0.05].结论 MSCs颈外静脉移植可以抑制MCT对大鼠肺损伤作用,减少ET-1的mRNA及血清ET-1的表达.     

盐酸戊乙奎醚对野百合碱致大鼠肺动脉高压的抑制作用

目的探讨盐酸戊乙奎醚是否能够减缓野百合碱导致的大鼠肺动脉高压及是否能够预防或缓解肺血管重构。方法 3~4周龄健康雄性SD大鼠30只,体重90~100g,随机均分为正常对照组(C组)、野百合碱肺高压组(M组)、盐酸戊乙奎醚组(P组),每组10只。M组和P组腹腔注射野百合碱60mg/kg建造大鼠肺动脉高压模型,C组腹腔注射等容量生理盐水。P组大鼠于建模前15min时腹腔注射盐酸戊乙奎醚2mg/kg,建模第2天腹腔注射盐酸戊乙奎醚1mg/kg,C组和M组在相应时点腹腔注射等容量生理盐水,连续使用3周。在建模后第21天,三组大鼠检测血流动力学(肺动脉压、右心室压);处死大鼠前采集静脉血以备血液生化检测:ELISA法检测一氧化氮(NO)含量、内皮素-1(ET-1)含量。处死大鼠后留取左肺组织行病理切片以观察肺组织病理形态学变化,取右肺组织于-80℃冻存以备后续检测。结果 M组和P组右心室SBP、平均肺动脉压、肺动脉SBP和肺动脉DBP明显高于C组(P0.05);P组右心室SBP、平均肺动脉压、肺动脉SBP和肺动脉DBP明显低于M组(P0.05)。M组肺小动脉明显增厚,肺小动脉管腔狭窄甚至闭塞,肺组织炎性细胞浸润非常明显。P组肺小动脉壁增厚减轻,肺组织炎性细胞浸润减轻。M组大鼠血清中NO含量明显低于,ET-1的含量明显高于C组(P0.05);P组大鼠血清中NO含量明显高于M组和C组(P0.05),ET-1含量明显高于C组,但明显低于M组(P0.05)。结论使用野百合碱成功建造了大鼠肺动脉高压模型,NO含量降低、ET-1含量增加可能与野百合碱致大鼠肺动脉高压的形成有关;盐酸戊乙奎醚减缓野百合碱致大鼠肺动脉高压模型的肺动脉压力的升高、改善肺小动脉壁增厚可能与增加NO含量、降低ET-1含量有关。     

藻蓝蛋白对野百合碱诱导肺动脉高压大鼠肺血管重构的影响

目的探讨藻蓝蛋白改善肺动脉高压(PAH)大鼠肺血管重构的机制。方法将30只雄性Sprague-Dawley(SD)大鼠, 采用随机数表法分为3组:正常对照组(对照组)、PAH模型组(PAH组)、藻蓝蛋白治疗组(治疗组), 每组10只。腹腔注射野百合碱(MCT)建立PAH模型, 治疗组在造模后第15天给予藻蓝蛋白灌胃, 持续14d。测量右心室收缩压(RVSP), 计算右心室肥厚指数(RVHI)。苏木精-伊红(HE)染色、马松(Masson)染色观察肺血管, 蛋白印迹法(Western blot)检测转化生长因子-β1(TGF-β1)、核转录因子-κB(NF-κB)、B淋巴细胞瘤-2(bcl-2)、bcl-2相关X蛋白(bax)、天冬氨酸特异半胱氨酸蛋白酶-3(Caspase-3)、α-肌动蛋白(α-SMA)、增殖细胞核抗原(PCNA)表达, 免疫荧光定位α-SMA和PCNA。多组比较采用单因素方差分析。结果治疗组RVSP、RVHI低于PAH组[(24.60±3.33) mmHg比(40.49±3.76) mmHg, F=140.998, P<0.01;(32.23±2.99)%比(...     

左肺反向循环逆转终末期肺动脉高压

目的 探讨反向肺循环逆转终末期肺动脉高压的机制.方法 选杂种犬30只,随机分成正常对照组(n=10)、肺动脉高压组(n=10)和肺高压反向组(n=10).观察各组的血流动力学参数、动脉血气、外周血一氧化氮(NO)、一氧化氮合酶(eNOS)、内皮素及其肺组织mRNA表达的变化.结果 终末期肺高压模型犬上行左肺反向循环手术后,平均肺动脉压(MPAP)降低[(17.3±3.5)mm Hg,P<0.01],但与正常犬MPAP[(12.6±4.2)mm Hg]相比仍偏高(P<0.05);动脉血氧分压上升到(96.5±6.4)mm Hg(P<0.01),血浆中eNOS升高[(1.53±0.56)μg/ml,P<0.01],NO分泌量增加[(36.25±6.94)μmol/L,P<0.01],ET的含量减少[(21.37±3.82)pg/ml,P<0.01].eNOS-mRNA在术后表达上调,PEET-mRNA在肺高压时表达上调,而在术后表达下调.结论 左肺反向循环具有可行性,可能通过转换血气交换的解剖位置、提高血氧含量、抑制血管收缩因子的产生,增加血管舒张因子的产生降低肺动脉高压.     

漂浮导管评估先天性心脏病重度肺动脉高压的作用

目的 研究漂浮导管评估先天性心脏病合并重度肺动脉高压的作用.方法 85例先天性心脏病合并重度肺动脉高压患者,男39例,女46例,年龄(22.8±16.5)岁,体重(46.4±12.1)kg,单纯室间隔缺损42例,房间隔缺损11例,室间隔缺损合并动脉导管未闭9例,动脉导管未闭7例,室间隔缺损合并房间隔缺损5例,其他11例.右侧锁骨下静脉或颈内静脉插入漂浮导管,动态监测肺动脉压、评估血流动力学,行急性肺血管反应试验和药物敏感试验.结果 与漂浮导管相比超声心动图对重度肺动脉高压诊断符合率差异无统计学意义(98.8％对100％,P＞0.05),评估肺动脉收缩压偏低[(118.2±44.7) mmHg(1mmHg=0.133kPa)对(139.5 ±32.3) mmHg,P＜0.05,),对艾森门格综合征诊断有较高假阳性率(8.4％对0,P＜0.01).漂浮导管测定平均肺动脉收缩压/平均肱动脉收缩压值1.22 ±0.35;平均肺动脉平均压/平均肱动脉平均压值1.07 ±0.11;肺血管总阻力(17.6±8.3)wood单位,剔除14例艾森门格综合征患者后肺血管总阻力为(11.3±3.7)wood单位,急性肺血管反应试验阳性67例,确诊艾森门格综合征14例.大量双向分流7例.漂浮导管检查中发生穿刺部位血肿2例.结论 漂浮导管检查评估肺动脉高压的程度、性质和血流动力学情况安全、准确,同时可进行急性肺血管反应试验和药物敏感试验,可为制定先天性心脏病合并重度肺动脉高压治疗方案提供客观依据.     

法舒地尔对肺血管重构的肺动脉高压大鼠的影响

目的 观察法舒地尔对发生肺血管重构的肺动脉高压(PAH)大鼠的影响.方法 将32只雄性Wistar大鼠随机均分为4组:对照3周组,模型3、6周组及治疗组;予野百合碱建模;治疗组于3周后予法舒地尔腹腔内注射.于3、6周末测定各组大鼠右心室收缩压(RVSP)、内皮素-1(ET-1)、N端脑钠素前体(NT-proBNP)、肺小动脉病理等.结果 (1)造模后RVSP随时间升高(31.2±7.6)、(43.3±8.3)、(56.9±6.9)mm Hg(1 mm Hg=0.133 kPa),治疗组(47.3±6.3)mmHg较模型6周组明显降低.(2)ET-1、NT-proBNP与RVSP呈正相关(r=0.721、0.454).(3)病理:造模后肺动脉平滑肌增生,管壁狭窄,至6周时近于闭塞,治疗组则明显好转.结论 对于已发生肺血管重构的PAH大鼠,法舒地尔能阻止肺动脉高压进展,ET-1、NT-proBNP可成为较理想的评估指标.

Abstract：

Objective To investigate the effects of Rho kinase inhibitor fasudil on monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) with vascular remodeling in rats. Methods Thirty-two male Wistar rats were randomly and equally divided into control group ( C3 ), MCT-PAH 3- and 6-week model groups (H3, H6 ) and fasudil-treated group (F6). The right ventricle systolic pressure( RVSP), right ventricle/left ventricle and septum[RV/( LV + S)], plasma endothelin-1 and NT-proBNP were measured; small pulmonary arterial morphometry, ratio of vascular wall thickness to vascular external diameter (WT) and ratio of vascular wall area to the total area (WA) were also observed. Results ( 1 )The RVSP was highest in H6 group, followed by F6 group, H3 group, and C3 group[(56. 9 ±6. 9), (47. 3±6.3), (43.3±8.3) and (31.2±7.6) mm Hg (1 mm Hg=0. 133 kPa)]. But no significant difference was found between H3 and F6 groups; (2) The levels of plasma ET-1 and NT-proBNP were positively associated with RVSP, RV/(LV +S), WT and WA (r for ET-1 was 0.721, 0.607, 0.652, 0.707,P＜0.01; r for NT-proBNP was 0. 454, 0. 330, 0. 365, 0. 398,P ＜0. 05); (3) Pathematological assessment showed that the thickness and muscularization of small pulmonary artery were increased in H3 group as compared with C3 group, most significantly in H6 group, and those were significantly decreased in F6 group as compared with H6 group. Conclusion Fasudil can improve the MCT-induced PAH with vascular remodeling in rats. The plasma ET-1 and NT-proBNP could be used as good makers to evaluate the severity of PAH.     

大鼠野百合碱肺高压模型血小板衍生生长因子mRNA的表达及作用

目的 观察血小板衍生生长因子(PDGF)A、B及其α,β受体在大鼠野百合碱肺高压模型中的表达,探讨PDGF在肺血管重构中的作用.方法 SD大鼠24只,体质量250～300g,随机分为野百合碱注射组(MCT,12只)和对照组(Con,12只).MCT组给与野百合碱60 mg/kg单次皮下注射.喂养6周后,使用逆转录-聚合酶链反应(RT-PCR)观察肺组织PDGF-A、PDGF-B及其α、β受体mRNA转录量的变化.结果 MCT组肺组织中PDGF-A、PDGF-B、PDGFR-α、PDGFR-β的mRNA转录水平都高于对照组(1.5609±0.1246比0.4057±0.0007,P＜0.05;0.4810±0.0733比0.2639±0.0070,P＜0.05:0.4963±0.0137比0.3038±0.0859,P＜0.05;1.1257±0.2490比0.0736±0.0185,P＜0.05).结论 血小板衍生生长因子(PDGF)-A、PDGF-B及其α、β受体活性表达的增强,参与了肺动脉高压肺血管重构的机制.     

银杏叶提取物对野百合碱所致肺动脉高压保护作用的实验研究

目的：探讨银杏叶提取物对野百合碱所致肺动脉高压（PAH）的早期保护作用。方法：30只雄性 SD大鼠随机分为3组：对照组、PAH 模型组和治疗组,每组10只。PAH 模型组和治疗组大鼠采用脊背部皮下注射1%野百合碱60 mg/kg的方法复制PAH 模型,注射后第2天开始每日予2 ml 0.9%氯化钠注射液（PAH 模型组）或60 mg/kg银杏叶提取物（治疗组）灌胃;对照组脊背部皮下注射等量溶剂,注射后第2天开始每日予2 ml 0.9%氯化钠注射液灌胃。第22天采用颈外静脉右心导管法测定平均肺动脉压（mPAP）、右心室收缩压（RVSP）,测定右心室、左心室、室间隔的重量,计算右心室肥厚指数（RVHI）;采用 HE染色观察肺细小动脉组织结构情况,并计算直径50~150μm的肺小动脉血管管壁厚度占血管厚度百分比（WA%）和血管管壁面积与血管面积比值（WV%）;采用免疫组化方法观察内皮型一氧化氮合成酶（eNOS）及内皮素-1（ET-1）在大鼠肺组织中的表达情况。结果：PAH 模型组、治疗组的 mPAP、RVSP、RVHI、WA%、WV%与对照组比较均明显升高（P〈0.05）,治疗组的 mPAP、RVSP、WA%、WV%较 PAH 模型组均降低（P〈0.05）,而治疗组与 PAH 模型组的RVHI差异无显著性。免疫组化结果显示,3组 eNOS表达,对照组〉治疗组〉PAH 模型组;3组 ET-1的表达, PAH 模型组〉治疗组〉对照组。结论：银杏叶提取物通过抑制 ET-1的合成、减轻内皮细胞损伤、维持 eNOS的表达,达到减缓PAH 进展的作用。     

L-arginine impacts pulmonary vascular structure in rats with an aortocaval shunt

BACKGROUND: The present study was designed to explore the therapeutic effect of L-arginine on the proliferation and apoptosis of pulmonary artery smooth muscle cells (SMCs) in high pulmonary blood flow-induced pulmonary hypertension and therefore to provide a basis for the mechanism by which L-arginine regulated pulmonary hypertension. MATERIALS AND METHODS: Twenty-one male SD rats were randomly divided into shunting group, shunting with L-arginine group, and control group. Abdominal aorta and inferior vena cava shunting was produced in rats of the shunting group and the shunting with L-arginine group. Pulmonary artery mean pressure (mPAP) and pulmonary vascular microstructure were analyzed. Immunohistochemistry for proliferative cell nuclear antigen (PCNA) and Fas expressions and TdT-mediated dUTP-biotin nick-end labeling (TUNEL) were used to detect cell proliferation and apoptosis, respectively. RESULTS: mPAP, RV/BW, and RV/LV + S were significantly increased in shunted rats compared to normal controls (P < 0.01, respectively). Pulmonary vascular structural remodeling developed in shunted rats. Proliferative index (PI), apoptotic index (AI), and the ratio of PI/AI of pulmonary artery SMCs in the rats of shunting group were elevated obviously (P < 0.01). Meanwhile, the expressing integral score of Fas was elevated in the shunting group (P < 0.01). However, L-arginine significantly attenuated pulmonary artery pressure and ameliorated pulmonary vascular structural remodeling. Also, it reduced PI and again augmented AI of pulmonary artery SMCs. The ratio of PI/AI was significantly reduced (P < 0.01). The expressing integral score of Fas was again augmented by L-arginine (P < 0.01). CONCLUSIONS: L-Arginine could inhibit proliferation and promote apoptosis of pulmonary artery SMCs in shunted rats.     

Pulmonary vascular changes after portasystemic shunt operation in rats

The prevalence of pulmonary hypertension among patients with portal hypertension, especially following a shunt operation, is significantly higher than that of primary pulmonary hypertension, suggesting the hypothesis that large portasystemic shunt plays a major role in development of pulmonary hypertension. To support this hypothesis, I studied experimentally the hemodynamic changes and the pathological findings in lung in 97 rats killed between one and 24 months after portasystemic shunt operations. The right ventricular systolic pressure (RVSP) and the right ventricular wall thickness were significantly high in the 82 rats raised over 3 months after the operations. In these rats the pathological findings in the lung revealed a thickness of pulmonary arterioles with medial hypertrophy, concentric intimal proliferation, and plexiform lesions. The values of endotoxin in central venous blood were significantly high and related with RVSP and shunt ratio. In pulmonary venous blood, thromboxane B2 increased and 6-keto PGF1a decreased. In conclusion, some of the rats developed pulmonary hypertension fter receiving a portasystemic shunt operation. It is suspected that endotoxin passing through the shunt plays a role in the development of pulmonary hypertension.     

Gene transfer of hepatocyte growth factor with prostacyclin synthase in severe pulmonary hypertension of rats

Objective: Hepatocyte growth factor (HGF) is a multi-potent growth factor, which has anti-fibrotic effects for lung injuries. In this study, we investigated whether human HGF gene transfer may attenuate the medial hypertrophy of pulmonary arteries and enhance the ameliorating effect of prostacyclin in monocrotaline (MCT)-induced pulmonary hypertension in rats. Methods and results: The day before MCT injection, HVJ-liposome complex with the cDNA encoding HGF gene (H group), PGIS gene (P group), and both HGF and PGIS gene (HP group) were transfected to the liver of rats as drug delivery system for the lung. Rats transfected with control vector served as controls (C group). Twenty-eight days after MCT injection, histological examination showed marked thickening of medial wall of pulmonary arteries and right ventricular hypertrophy. Percent medial wall thickness (%WT) of peripheral pulmonary arteries, pressure ratio of the right ventricle (RV) to the left ventricle (LV), and weight ratio of the RV to the LV plus septum were significantly increased in the control. Percent medial wall thickness was significantly ameliorated in H group and HP group in comparison with C group. Pressure and weight ratio of RV to LV was significantly ameliorated in P group and HP group in comparison with C group, and was significantly ameliorated in HP group than P group. Conclusions: In vivo gene transfection with HGF gene attenuated the medial hypertrophy of pulmonary arteries and enhanced the ameliorating effect of prostacyclin for pulmonary hypertension in MCT rats. Thus, gene therapy with HGF and PGIS may be a promising strategy for severe pulmonary hypertension.     

Inhaled carbon monoxide abrogates pulmonary hypertension

Background: Pulmonary hypertension poses a significant clinical challenge. Our current therapies are limited and not efficacious. Carbon monoxide (CO), which is produced endogenously by heme oxygenases, has been shown to possess vasoregulatory properties. Therefore, we hypothesized that inhaled low dose CO would prevent and reverse pulmonary vascular hyperplasia and right ventricular hypertrophy (RVH) in an animal model of pulmonary hypertension. Methods: Monocrotaline (MCT)-treated rats were divided into 4 groups (n = 3-6 per group). Group A received MCT (50 mg/kg, s.c.) alone. Group B was treated with 1 hour daily of inhaled CO (250 ppm) days 1-14 after MCT administration. Group C received CO from days 15-28 and Group D received CO from days 29-42. All animals were sacrificed on day number 43 and their hearts and lungs harvested for morphometric and histologic evaluation. Body weight, right and left ventricular masses, and mean pulmonary arterial pressure (mPAP) were evaluated. Results: MCT caused progressive pulmonary hypertension. By day 42, MCT-treated rats had a mPAP of 35 ± 3.3 compared to untreated controls whose mPAP was 16 ± 2.1 and CO-treated rats which had a mPAP of 20 ± 7.1 (p < 0.05, ANOVA). CO prevented RVH in all treatment groups, even when normalized for body weight (Table) (p < 0.05, Fisher’s Least Significant Difference). Rats treated with MCT alone displayed significant muscularization of the ventricular wall and pulmonary neointimal hyperplasia; CO therapy abrogated these effects. Conclusion: Our data show that low dose inhaled CO decreases mPAP, and prevents RVH and vascular changes in MCT-induced pulmonary hypertension. CO therapy was effective even after the development of cardiac and pulmonary disease. CO may be a useful adjunct in the treatment or prevention of pulmonary hypertension.