黄芪对大鼠缺氧性肺动脉高压功能形态学的影响

为观察黄芪对缺氧性大鼠腺泡内肺动脉构形重组和肺动脉高压是否具有阻抑效应，以期为该药在肺动脉高压的防治方面提供实验依据。在常压低氧条件下，选用６０只大鼠，分低氧组、低氧加黄芪组和正常组，在实验第１５天、３０天分别测量右心室收缩压，计算右心室肥大指数、光镜与电镜观察肺血管病变及进行显微形态计量学检测，动态观察了黄芪对低氧大鼠腺泡内肺动脉构形重组及肺动脉高压的影响。结果显示黄芪不仅能拮抗缺氧性腺泡内肺动脉收缩，减轻低氧对肺动脉壁细胞的损伤，还能阻抑腺泡内肺动脉中膜肌化增强和外膜纤维母细胞增生。说明黄芪有明显阻抑低氧性腺泡内肺动脉构形重组和预防缺氧性肺动脉压升高的作用。     

慢性缺氧时肺腺泡内动脉结构变化与血流动力学变化的关系

在用低压舱模拟连续低压缺氧不同时间的大鼠模型上,观察分析了肺腺泡内动脉结构重建变化与肺循环血流动力学变化的关系。结果表明:缺氧早期(24h后),肺腺泡内动脉即有明显肌化(肌性动脉段增多,非肌性动脉段减少)。随缺氧时间延长,肺腺泡内动脉肌化与肺动脉压增高及右心室代偿性肥厚密切相关。构成肺腺泡内动脉的三种血管段随缺氧时间延长有不同变化趋势,反映出缺氧早期肌性动脉段增多主要经原有部分肌性动脉段转变为肌性动脉段的短捷途径;以后非肌性动脉段经部分肌性动脉段转变为肌性动脉段逐渐成为主要途径。     

先天性心脏病伴肺动脉高压肺组织中腺泡内动脉转化生长因子-β1 mRNA和内皮素-1 mRNA的表达及意义

目的探讨转化生长因子-β1(TGF-β1)和内皮素-1(ET-1)在先天性心脏病(先心病)伴肺动脉高压(PH)的肺组织腺泡内肺动脉中的表达及意义.方法收集51例肺组织,其中41例为左向右分流型先心病患儿[伴PH 25例(A组),无PH 16例(B组)],对照组10例(C组),应用原位杂交、图像分析检测51例腺泡内肺动脉(IAPA)TGF-β1 mRNA和ET-1 mRNA的表达及平均吸光度值(A值);透射电镜观察肺组织超微结构;弹力纤维(VG)染色显示腺泡内肺动脉并计算其数量的变化.结果 (1)肺腺泡内部分肌型及环肌型动脉的数量,A、B两组分别与C组比较, F值分别为149.96、142.01,P<0.01;(2)电镜观察,有的肺小动脉内皮细胞增生;中膜平滑肌增厚,平滑肌细胞面积增大;外膜胶原纤维密集;毛细血管基膜增厚;(3)原位杂交发现,TGF-β1 mRNA在A、B两组腺泡内肺动脉均有阳性表达,A值分别为(0.1988±0.0498)、(0.1098±0.0428),C组表达微弱(A值=0.0578±0.0096),A、B、C三组间比较差异有统计学意义(P<0.05);ET-1 mRNA 在A、B两组肺腺泡内肺动脉内皮细胞表达明显增强,A值分别为(0.1692±0.0205)、(0.1004±0.0140),C组仅有微弱表达(A值=0.0746±0.0119),A、B、C三组间比较差异有统计学意义(P<0.01).结论左向右分流型先心病患儿肺组织腺泡内部分肌型及肌型动脉数量明显增加,肺血管结构重组,TGF-β1 mRNA、ET-1 mRNA表达增高与先心病伴PH的发生有关系.     

低氧对肺动脉平滑肌和内皮细胞蛋白激酶C α mRNA表达的影响

目的：探讨低氧对肺动脉平滑肌和内皮细胞蛋白激酶C(PKC)αmRNA表达的影响。方法：应用原位杂交技术了大鼠不同节段肺动脉平滑肌细胞和内皮细胞PKCαmRNA的分布及低氧对在体和离体肺动脉平滑肌细胞及内皮细胞PKCαmRNA表达的影响。结果：正常大鼠各级肺动脉平滑肌细胞和内皮细胞均有PKCαmRNA的表达,腺泡内肺动脉平滑肌细胞中的表达明显高于肌型肺动脉（P＜0．01）,低氧14d和28d肌型动脉和腺泡内肺动脉内皮细胞的表达均明显增高（P＜0．01）,腺泡内腺动脉平滑肌细胞的表达较对照组明显升高（P＜0．01）,低氧14d肌型肺动脉平滑肌细胞表达升高不明显,但低氧28d明显升高（P＜01）,正常条件下离体培养猪肺动脉平滑肌细胞和内皮细胞均有PKCαmRNA的表达,低氧1h对其表达无明显影响,48,72h表达明显升高,以72h升高最显著（P＜0．001）,结论：低氧可促进肺动脉平滑肌细胞和内皮细胞PKC amRNA 的表达,而以腺泡内肺动脉平滑肌细胞的变化最明显,PCKα在低氧性肺动脉高压的形成中可能起一定作用。     

慢性低氧性肺动脉高压大鼠肾上腺髓质素前体N端20肽的变化

目的：探讨慢性低氧性肺动脉高压和肺血管结构重建时肾上腺髓质素前体N端20肽（PAMP）的变化。方法:将18只雄性Wistar大鼠随机分为对照组和低氧组，每组各9只。常压低氧2周后，以右心导管法测定肺动脉平均压（mPAP），检测右心室与左心室加室间隔比值 ［RV/(LV+S)］，观测肺血管显微和超微结构的变化。并且以放免法测定血浆中PAMP含量，以免疫组化法检测肺组织中PAMP表达，以原位杂交检测肺组织中肾上腺髓质素（ADM） mRNA的表达。结果: 低氧组大鼠mPAP及RV/（LV+S）均明显高于对照组（均P<0.01）。光镜下，肺小血管肌化程度明显增强，肺中、小型肌型动脉相对中膜厚度明显增加。电镜下，肺腺泡内动脉内皮细胞增生、肿胀，内弹力层粗细不均，平滑肌细胞肥厚、向合成表型转化。并且低氧组大鼠血浆PAMP含量明显高于对照组（P<0.01），肺动脉PAMP表达和ADM mRNA表达均明显增强。结论：低氧后肺动脉PAMP表达和血浆PAMP含量的上调可能参与了慢性低氧性肺动脉高压和肺血管结构重建的形成。     

不同缺氧时间对大鼠近、远端肺动脉内皮结构的影响及其意义

主肺动脉和末梢肺动脉(肺腺泡内动脉—IAA)结构上存在很大差别。前者为弹性动脉;后者则不仅截面积巨大,且包括肌性动脉(MA),部分肌性动脉(PMA)和非肌性动脉(NMA)三种结构,尤以NMA最多.故在维持肺循环低压、低阻、高灌注上起着重要作用.本实验旨在观察探讨不同缺氧时间该两段肺动脉内皮(EC)结构变化的异同及在肺动脉高压发生发展中的意义。Wistar大鼠分为平原对照和连续低压缺氧(5000m)1、7、21和40d组(n=7～12).测肺动脉平均压(mPAP),利用生物测定法记录右肺外动脉环对不同浓度Ach的舒张反应,光镜记录IAA中MA％、PMA％及NMA％和肺泡区φ     

野百合碱引起肺血管重建的观察

目的和方法:一次性腹腔注射野百合碱(MCT)(60mg/kg体重),建立大鼠肺心病模型。利用光镜、电镜技术测量观察肺血管重建时内皮细胞、肺小动脉、心脏等变化情况。从形态学改变方面探讨肺动脉高压时肺血管重建的机制。结果:肺血管内皮细胞损伤;小血管血小板性血栓形成;动脉弹力膜断裂;血管平滑肌细胞增生、迁移、转型;肺血管肌化、改建,其中以肺腺泡内动脉的变化尤为突出。右心室明显肥大。结论:一次性注射MCT即可引起肺血管损伤、重建,导致肺心病;在此过程中,血管内皮细胞起着关键作用;肌化增强的肺动脉中膜平滑肌细胞可能来源于周细胞和原位的中间细胞。     

门冬氨酸钾镁对低氧性肺动脉高压大鼠肺组织血栓素A2、前列环素及肺腺泡内动脉结构的影响

慢性低氧性肺动脉高压(HPH)的形成与腺泡内肺小动脉内皮增生、肥厚及无肌型动脉向肌型动脉转化有关[1]。血栓素A2(TXA2)、前列环素(PGI2)之间存在相互调控关系,对HPH起着重要的作用。门冬氨酸钾镁是门冬氨酸钾盐与镁盐的等量混合物,目前临床上广泛应用于治疗心血管疾病。本实验建立慢性HPH大鼠模型,旨在观察门冬氨酸钾镁对低氧性肺血管结构重建(HPVR)及肺组织TXA2、PGI2含量的影响,探讨低氧性肺血管结构重建的机制及防治作用。材料与方法1雄性Wistar大鼠21只,体质量210～310g,随机分对照组,低氧组[大鼠置在常压低氧舱内,氧浓度在…     

4种肺动脉高压动物模型肺血管重构模式的差异研究

目的：探讨4种肺动脉高压（PH）动物模型肺血管重构模式的差异。方法:雄性SD大鼠（350-400g），分别通过腹主动脉-腔静脉分流（A-VF, n=10）、左肺切除（PE, n=10）、野百合碱注射（MCT, n=10）、左肺切除+MCT（PE+MCT,n=12）4种方法建立PH模型。检测平均肺动脉压力(mPAP）、RV/(LV+S)重量比值、肺小动脉中膜厚度百分比（WT%）、无肌性动脉肌化程度和新生内膜(neointima)形成、新生内膜增殖度和血管阻塞计分（VOS）。结果:在PE+MCT组（肺切除术后5周，MCT注射后4周）右肺腺泡内血管出现了新生内膜病变，其它组均没有新生内膜病变形成。PE+MCT组的动物出现了严重的右心室肥大，动脉中膜明显增厚，平均肺动脉压（mPAP）和无肌性血管肌化程度显著增加；A-VF、PE和MCT组仅形成轻-中度的右心室肥大、mPAP升高和小动脉肌化。结论:左肺切除联合应用MCT能成功诱导大鼠PH新生内膜模型，该模型能更好地模拟人类严重PH的病理改变，是研究梗阻性PH更为适用的动物模型。     

高肺血流量所致肺动脉高压大鼠肺血管结构和气体信使分子的变化

目的:探讨高肺血流量所致肺动脉高压大鼠肺血管结构和两种气体信使分子的变化。方法:对大鼠行腹主动脉-下腔静脉分流术。11周后,以右心导管法测定肺动脉平均压(PAMP)。检测右心室/体重(RV/BW)和右心室/左心室+室间隔(RV/LV+S)比值。观测肺血管显微及超微结构的变化。并且以分光光度计测定血浆一氧化氮(NO)和一氧化碳(CO)含量,以免疫组织化学方法检测肺动脉内皮细胞内皮型NO合酶(eNOS)和平滑肌细胞血红素加氧酶-1(HO-1)的表达。结果:分流组大鼠PAMP、RV/BW及RV/(LV+S)比值明显高于对照组(P均<001)。光镜下,肺小血管肌化程度明显增强,肺中、小型肌型动脉相对中膜面积及厚度明显增加。电镜下,肺腺泡内动脉内皮细胞增生、变性,内弹力层粗细不均,平滑肌细胞肥厚、向合成表型转化。并且分流组大鼠血浆NO含量明显高于对照组(P<001),肺动脉内皮细胞eNOS表达明显增强。而分流组大鼠血浆CO含量和肺动脉平滑肌细胞HO-1表达与对照组相比无明显变化。结论:肺血管结构重建是左向右分流所致肺动脉高压的重要病理基础,NO体系可能在其形成中起重要的调节作用。     

低氧致鼠腺泡内肺动脉PDGF—B链蛋白表达的变化

目的：探讨血小板源性生长因子（ＰＤＧＦ）在低氧肺动脉高压血管构形重建发生中的作用。方法：应用免疫组化技术结合计算机图像分析，检测了低氧大鼠腺泡内肺动脉（ＩＡＰＡ）ＰＤＧＦ－Ｂ链蛋白表达水平。结果：常氧时，ＩＡＰＡ仅有ＰＤＧＦ－Ｂ链蛋白弱表达；低氧１天时，ＩＡＰＡ便有较强的ＰＤＧＦ－Ｂ链蛋白表达，定位于ＩＡＰＡ的内皮和中膜，低氧３天至１４天仅分布于中膜；低氧１、３、５、７、１４天各时间点ＰＤＧＦ－Ｂ链蛋白表达分别为常氧组的１．５３、１．５９、１．５６、１．６２和１．４２倍，差异有显著性（Ｐ＜０．０１）。结论：ＰＤＧＦ－Ｂ链蛋白可能参与了低氧肺动脉高压血管构形重建的发病过程     

Anti-topoisomerase II alpha autoantibodies in systemic sclerosis-association with pulmonary hypertension and HLA-B35

We have previously detected autoantibodies against topoisomerase II alpha (anti-topo II alpha) in sera from patients with idiopathic pulmonary fibrosis. To determine whether anti-topo II alpha is also present in systemic sclerosis (SSc) patients with pulmonary involvement, we screened sera from 92 patients and 34 healthy controls. Presence of anti-topo II alpha was investigated with respect to clinical and serological features, including the frequencies of HLA class I and II alleles. Anti-topo II alpha was detected in 20/92 (21.7%) patients. No association was found with either anti-topoisomerase I (Scl-70 or anti-topo I) or anti-centromere antibodies. However, anti-topo II alpha was associated with the presence of pulmonary hypertension (PHT) (as opposed to pulmonary fibrosis), and with a decrease of carbon monoxide diffusing capacity. Anti-topo II alpha was strongly associated with the presence of the class I antigen HLA-B35. No significant association was found with HLA class II antigens. HLA-B35 also turned out to be associated with the presence of PHT. These results indicate that in SSc patients, the presence of anti-topo II alpha is associated with PHT, and that the simultaneous presence of HLA-B35 seems to add to the risk of developing PHT.     

低氧诱导因子-1α和内皮素-1基因在大鼠低氧性肺动脉高压中的表达

目的　探讨低氧诱导因子 1(HIF 1α)和内皮素 1(ET 1)基因表达在低氧性肺动脉高压发病过程中的变化和作用。方法　复制低氧性肺动脉高压大鼠模型 ,测定平均肺动脉压 ,弹力纤维染色显示腺泡内肺动脉 ,用放射免疫法测ET含量 ,原位杂交方法进行检测HIF 1αmRNA。结果　HIF 1αmRNA在低氧各组腺泡内肺动脉有表达 ,低氧 14d组 (0 2 5 6 9± 0 0 46 8)和低氧 2 8d组 (0 2 2 5 8±0 0 45 3)染色强于低氧 5d组 (0 145 5± 0 0 2 72 )和正常组 (0 110 9± 0 0 2 2 4) ;ET 1mRNA在低氧各组腺泡内肺动脉有表达 ,低氧 14d组 (0 412 2± 0 0 783)和低氧 2 8d组 (0 36 84± 0 0 72 9)染色强于低氧5d组 (0 2 0 17± 0 0 34 9)和正常组 (0 185 5± 0 0 36 1) ,HIF 1α和ET 1基因表达在H14d组和H2 8d组明显增加 (P <0 0 5 )。肺动脉血中ET 1含量在H14d组 [(15 8 78± 2 5 14)pg/ml]和H2 8d组 [(142 93± 2 3 38)pg/ml]明显高于H5d组 [(79 6 8± 12 5 4)pg/ml]和正常组 [(6 5 37± 10 82 )pg/ml](P <0 0 5 ) ;H14d组 [(34 0± 5 8)mmHg]和H2 8d组 [(2 9 0± 4 7)mmHg]的mPAP也明显高于H5d组[(19 0± 3 5 )mmHg]和正常组 [(17 0± 2 8)mmHg](P <0 .0 5 ) ,并且与肺动脉血中ET 1含量呈正比(rs=0     

NF-κB的活性和iNOS基因表达在低氧性肺动脉高压中的变化

目的：探讨NF-κB的活性及iNOS基因表达在低氧性肺动脉高压（HPH）发病过程中的变化。方法：复制低氧性肺动脉高压大鼠模型，用免疫组化、原位杂交、半定量逆转录-聚合酶链式反应（RT-PCR）和Western blot等方法进行检测。结果：iNOS mRNA在腺泡内肺动脉（IAPA）的表达，低氧28 d（H28d）组染色强于正常（N）组、低氧5 d（H5d）组和低氧14 d（H14d）组。半定量RT-PCR证实低氧肺组织iNOS mRNA含量在H28d组分别是N组、H5d组和H14d组的2.1倍、1.9倍和1.8倍。H28d组肺组织NF-κB的核染色增多，I-κBα的含量在N组、H5d组和H14d组分别是H28d组的2.7倍、2.8倍和2.5倍。结论：在HPH中NF-κB的激活可能与低氧肺血管构建及iNOS mRNA的表达有关。     

Modulation of actin isoform expression in alveolar myofibroblasts (contractile interstitial cells) during pulmonary hypertension.

Lungs of 37 patients with pulmonary hypertension (PHT), 5 normal human lungs, and 30 normal rat lungs, were studied using immunohistochemical stainings for actin, alpha-smooth muscle (alpha-SM) actin and desmin. The type of PHT was determined on clinicopathologic grounds (in 17 cases by catheterism); 20 patients had precapillary and 17 postcapillary PHT. In normal lungs, myofibroblasts, ie, contractile interstitial cells (CIC), distributed in alveolar septa, were not stained by alpha-SM actin antibodies. Only around the venules, were cells labeled by this antibody present. Furthermore, there were bundles of alpha-SM actin-positive cells around the openings of air sacculi into the alveolar ducts. In precapillary PHT, the distribution and immunostaining properties of interstitial cells remained unchanged; alpha-SM actin-positive cells were observed in thickened arterial intima and in plexiform lesions. In postcapillary PHT secondary to heart failure, to mitral stenosis, or in veno-occlusive disease, many interstitial cells in the alveolar septa were decorated by alpha-SM actin antibodies but not with desmin. The authors propose that, in postcapillary PHT, mechanical stretch due to capillary congestion may be responsible for the generation of cells that express an actin isoform associated with smooth muscle.     

Adaptative modifications of right coronary myocytes voltage-gated K+ currents in rat with hypoxic pulmonary hypertension

Chronic hypoxia (CH)-induced pulmonary hypertension (PHT) is well known to alter K+ channels in pulmonary myocytes. PHT induces right ventricle hypertrophy that increases oxygen demand; however, coronary blood flow and K+ channel adaptations of coronary myocytes during PHT remain unknown. We determined whether CH and PHT altered K+ currents and coronary reactivity and what impact they might have on right myocardial perfusion. Right ventricle perfusion, as attested by microspheres, was redistributed toward hypertrophied right ventricle [RV/LV (%)=0.59+/-0.07% in CH rats vs. 0.29+/-0.03 in control rats, P<0.05]. Whole-cell patch clamping showed a reduction of global outward current in hypoxic right coronary artery myocytes (H-RCA), whereas hypoxic left coronary artery myocytes exhibited an increase. K+ channel blockers revealed that a 4-aminopyridine (4AP)-sensitive current (Kv current) was decreased in H-RCA (14.3+/-1.1 vs. 23.4+/-2.5 pA/pF at 60 mV in control RCA, P<0.05) and increased in hypoxic left coronary artery myocytes (H-LCA; 26.4+/-3.8 vs. 11.8+/-1.6 pA/pF at 60 mV in control LCA, P<0.05). Constriction to 4AP was decreased in H-RCA when compared to normoxic control and increased in H-LCA when compared to LCA. Finally, we observed that the expression of Kv1.2 and Kv1.5 were lower in H-RCA than that in H-LCA. This study reveals that CH differentially regulates Kv channels in coronary myocytes. Hypoxia decreases Kv currents and therefore reduces vasoreactivity that contributes to an adaptative response leading to right hypertrophied ventricle perfusion enhancement at rest.     

标准化粉尘螨疫苗免疫治疗哮喘小鼠肺组织病理变化动态观察

目的对标准化粉尘螨疫苗免疫治疗哮喘小鼠肺组织的病理变化进行观察,以进一步探讨标准化粉尘螨疫苗免疫治疗疗效。方法利用粉尘螨抗原建立哮喘小鼠模型,将32只小鼠分为4组：对照组、哮喘组、低剂量治疗组、高剂量治疗组。末次激发后24h,处死动物,取小鼠肺组织,分别固定、包埋和切片,用光镜、电镜观察肺组织病理变化。结果光镜下哮喘组相对于空白组,肺组织结构紊乱、充血以及水肿,有大量炎症细胞浸润;高剂量粉尘螨疫苗治疗组较哮喘组肺组织病理变化有明显改善,炎性细胞浸润显著减少,水肿较轻。而低剂量粉尘螨疫苗组肺组织仍可见明显炎性细胞浸润和病变,但较哮喘组病理变化为轻。电镜观察显示：哮喘组肺组织结构紊乱,有炎性细胞浸润,而高剂量粉尘螨疫苗治疗组Ⅰ型和Ⅱ型肺泡细胞结构基本正常、清晰。结论粉尘螨疫苗能有效减轻哮喘小鼠肺组织的病理变化,减少炎症细胞浸润,且高剂量粉尘螨疫苗较低剂量治疗疗效更为显著,为临床过敏性哮喘尘螨脱敏治疗奠定理论基础。     

Persistence, re-expression, and induction of pulmonary arterial fibronectin, tropoelastin, and type I procollagen mRNA expression in neonatal hypoxic pulmonary hypertension.

Changes in the structure and function of muscular pulmonary arteries are crucial for normal adaptation to extrauterine life and rapid changes in matrix protein gene expression are likely necessary for this adaptation. We hypothesized that pathological stimuli imposed at the time of birth would alter developmental changes in matrix protein gene expression thereby affecting the normal post-uterine changes in pulmonary hemodynamics. We used in situ hybridization to examine the normal developmental expression of three extracellular matrix protein mRNAs, fibronectin, tropoelastin, and alpha 1 (I) procollagen, in muscular pulmonary arteries of both fetal and neonatal calves and assessed the impact of severe hypoxia-induced pulmonary hypertension on their expression. Morphometric techniques were used to assess whether changes in matrix protein mRNA levels were related to changes in matrix fiber accumulation. Exposure to chronic hypoxia postnatally resulted in the persistence, reexpression, and induction of fibronectin, tropoelastin, and alpha 1 (I) procollagen mRNAs, respectively, in muscular pulmonary arteries. In each case the hybridization signal was localized primarily to the adventitial layer of the vessel. Morphometric analysis showed that the increased hybridization signals seen correlated with an increase in both vascular elastin and collagen fiber volumes in the adventitial layer. We conclude that the change in expression of matrix genes in the pulmonary artery wall during exposure to chronic hypoxia is an important adaptive response to changes in hemodynamic factors and/or oxygen tension. The unchecked increase in matrix protein expression seen likely contributes to the pathological pulmonary arterial structural remodeling and loss of vasoreactivity that occurs during the development of severe neonatal pulmonary hypertension.