764-3对野百合碱性肺动脉高压大鼠肺动脉胶原沉积的影响

目的：观察７６４－３对野百合碱（ＭＣＴ）性肺动脉高压大鼠肺动脉胶原沉积的影响，探讨其可能的作用机制。方法：将雄性Ｗｉｓｔａｒ大鼠随机分为４组即正常组，正常给药组，ＭＣＴ对照组，ＭＣＴ给药组。给药大鼠从第１５天起，皮下注射７６４－３（４０ｍｇ／ｋｇ）１次／日。实验结束时，行血流动力学和病理形态学检查，并测定肺动脉羟脯氨酸（ＨＹＰ）和总蛋白含量。结果：ＭＣＴ性肺动脉高压大鼠肺动脉羟脯氨酸含量较正常组明显增高，平均分别为２４９．５±４９．９μｇ和１２４．２±２１．７μｇ（Ｐ＜０．００１），泡内肺肌型动脉中膜平滑肌细胞（ＳＭＣ）肥大、呈分泌型改变，细胞间胶原沉积；７６４－３能显著降低肺动脉羟脯氨酸含量（平均由２４９．５±４９．９μｇ降至１８６．８±３８．５μｇ，Ｐ＜０．０１），中膜ＳＭＣ结构逆转，胞体多细长，细胞间胶原减少。结论：７６４－３能部分抑制胶原在肺动脉壁的过度沉积，降低ＭＣＴ性肺动脉高压。而其减少胶原沉积、降低肺动脉高压的机制，很可能是通过逆转中膜ＳＭＣ表型改变     

肺动脉高压大鼠不同肺病理改变情况下右心室及肺动脉压力频谱的特征

目的：探讨肺动脉高压（ＰＨ）大鼠的右心室及肺动脉压力频谱特征。方法：雄性Ｗｉｓｔａｒ大鼠４３只，分为４组。其中正常对照组１０只；其余分为３组，即单纯缺氧组、一氧化氮治疗组［每天１２小时吸入空气中含有２０ｐｐｍ（１ｐｐｍ＝１／１０６）浓度的一氧化氮］和７６４－３治疗组（４０ｍｇ／ｋｇ体重，每日１次，腹腔注射），每组各１１只。观察３周后，经颈外静脉插管测量右心室及肺动脉压力并数字化输入微机，计算得其频谱特征。每只大鼠均行肺病理观察计数肌型、部分肌型和无肌型肺小动脉数目占全部观察肺小动脉数的百分比。比较压力在心率谐波上的频谱差异。结果：以肌型肺小动脉占病理观察肺小动脉总数的百分比为指标，单纯缺氧组的病理改变程度最重，其次为７６４－３治疗组和一氧化氮治疗组。右心室及肺动脉压力频谱特征的差异主要表现在零频幅值和前２次谐波幅值间的不同，且右心室压频谱的改变较肺动脉压明显。结论：同时观察右心室和肺动脉压幅度谱可以估测肺动脉高压的可复性程度。作者并就其影响因素进行了讨论。     

两种一氧化氮合酶抑制剂在内毒素肝损伤中的作用

材料与方法：内毒素（ＬＰ）（Ｄｉｆｉｃｏ,美国）硝基左旋精氨酸（Ｌ－ＮＮＡ）（Ｓｉｇｍａ）,Ｓ－硫酸甲基异硫脲素（ＳＭＴ,Ｓｉｍａ）,丙氨酸转氨酶（ＡＬＴ）测定试剂盒（上海荣胜生物制剂厂）。Ｗｉｓｔａｒ大鼠（重庆医科大学实验动物中心）雄性,体重２００～３００ｇ。动物分为４组,第１组腹腔注射灭菌生理盐水１ｍｌ;第２组腹腔注射ＬＰＳ（４ｍｇ／ｋｇ）;第３组在腹腔注射ＬＰＳ（４ｍｇ／ｋｇ）前１小时,动物先腹腔注射Ｌ－ＮＮＡ（１００ｍｇ／ｋｇ）;第４组注射ＬＰＳ（４ｍｇ／ｋｇ）前２小时,腹腔注射ＳＭＴ（…     

一氧化氮在肝损伤中作用的实验研究

材料与方法：１．动物模型的复制及分组：雄性ｗｉｓｔａｒ大鼠,随机分成六组。除正常对照组外,各组均给予１０％Ｄ－半乳糖胺（Ｄ－Ｇａ１Ｎ）０．６ｇ／ｋｇ及大肠杆菌Ｏ１１１Ｂ４脂多糖（ＬＰＳ）０．１ｍｇ／ｋｇ腹腔注射,造成大鼠急性肝损伤模型。并分别于给Ｄ－ＧａｌＮ前２０分钟及后６小时、１１小时,精氨酸（Ａｒｓ）组给子Ｌ－Ａｒｇ０．５ｇ／ｋｇ腹腔注射;Ａｒｇ一硝基精氨酸甲酯（ＮＡＭＥ）组给予Ｌ－Ａｒｇ０．５ｇ／ｋｇ加Ｌ一ＮＡＭＥ５０ｍｇ／ｋｇ;ＮＡＭＥ组给予Ｌ－ＮＡＭＥ１０ｍｇ／ｋｇ;地塞米松（Ｄｅｘ）…     

内源性一氧化氮对犬急性缺氧性肺动脉高压的影响

利用一氧化氮合成酶抑制剂——Ｎ￣Ｇ－硝基－Ｌ－精氨酸甲酯（Ｌ－ＮＡＭＥ）观察内源性一氧化氮对犬急性缺氧性肺血管收缩的影响。Ｌ－ＮＡＭＥ（１、５、１５ｍｇ／ｋｇ）可显著增加缺氧时肺动脉平均压（ｍＰＡＰ）和肺血管阻力（ＰＶＲ），其作用维持９０～１８０分钟。与用药前缺氧时比较，ｍＰＡＰ最大可分别升高１．１±０．２、１．５±０．３、１．６±０．４ｋＰａ（１ｋＰａ＝７．５ｍｍＨｇ），而ＰＶＲ最大可分别升高５８．４±１５．６、９９．３±２８．８、７８±４．０ｋＰａ·ｓ／Ｌ，Ｌ－ＮＡＭＥ１５ｍｇ／ｋｇ升ｍＰＡＰ的作用明显强于１ｍｇ／ｋｇ组。Ｌ－精氨酸（０．５ｇ／ｋｇ）可逆转Ｌ－ＮＡＭＥ（５ｍｇ／ｋｇ）增强缺氧性肺血管收缩的作用。此外，Ｌ－ＮＡＭＥ也可明显增加缺氧时股动脉平均压和全身血管阻力，同时减少心输出量，减慢心率，结果提示内源性一氧化氮可能具有抑制急性缺氧性肺血管收缩的作用。     

波生坦对糖尿病大鼠的肾脏保护作用

目的：观察非选择性内皮素受体拮剂波生坦（Ｂｏｓｅｎｔａｎ）对糖尿病ＳＤ大鼠的肾脏保护作用。方法：设糖尿病非治疗组（ＤＭ组）、糖尿病Ｂｏｓｅｎｔａｎ治疗组（ＤＭ－Ｂ组）及正常对照组（ＳＤ组）,每组６只大鼠。予ＳＤ大鼠一次性腹腔注射链脲佐菌素６５ｍｇ／ｋｇ,诱导建立糖尿病模型。在ＤＭ－Ｂ组中,予大鼠Ｂｏｓｅｎｔａｎ１００ｍｇ／（ｋｇ．ｄ）灌胃,持续４周。４周后观察各组大鼠体重、肾重、平均动脉压、２４ｈ     

螺内酯预防L-硝基精氨酸诱导持续性高血压大鼠心肌重塑

目的：探讨醛固酮受体拮抗剂螺内酯（ｓｐｉｒｏｎｏｌａｃｔｏｎｅ，安体舒通）预防一氧化氮减少致高血压心肌重塑的可行性。方法：取８周龄雄性Ｗｉｓｔａｒ大鼠１９只，随机分成高血压大鼠实验组１２只，其中又分为高血压组、预防组各６只；正常血压对照组７只。高血压大鼠实验组用Ｌ－硝基精氨酸（Ｎ－ｏｍｅｇａ－ｎｉｔｒｏ－Ｌ－ａｒｇｉｎｉｎｅ，ＬＮＮＡ，７．５ｍｇ／ｋｇ，腹腔注射，每日２次，共４周）诱导高血压心肌重塑大鼠１２只，其中６只同时以安体舒通（２０ｍｇ／ｋｇ，每日１次，灌胃，共４周）治疗。分别观察其动脉血压、左心室相对重量、丝裂素活化蛋白激酶（ｍｉｔｏｇｅｎ－ａｃｔｉｖａｔｅｄｐｒｏｔｅｉｎｋｉｎａｓｅ，ＭＡＰＫ）活性、胶原蛋白含量、亚硝酸盐浓度、心肌组织形态学改变等。结果：高血压组亚硝酸盐浓度降低，血压、ＭＡＰＫ活性及胶原蛋白含量均明显升高，左心室肥大，心肌细胞肥大及心肌纤维化。安体舒通可明显降低动脉压、ＭＡＰＫ活性，减轻左心室肥大、心肌细胞肥大及心肌纤维化。结论：安体舒通通过竞争性抑制醛固酮与其受体结合，降低ＭＡＰＫ活性，可防止一氧化氮生成减少所致高血压心肌重塑及血压持续升高。     

单克隆抗体和吡喹酮协同杀伤日本血吸虫的初步研究

昆明系小白鼠人工感染日本血吸虫尾蚴前２ｈ，４组口服低剂量吡喹酮（吡２０ｍｇ／ｋｇ或吡５０ｍｇ／ｋｇ），并被动免疫转移抗日本血吸虫单抗（ＭｃＡｂ１４或ＭｃＡｂ２４），其减虫率分别为４５．４０％（ＭｃＡｂ１４＋吡２０ｍｇ／ｋｇ）４５．７４％（ＭｃＡｂ＋吡２０ｍｇ／ｋｇ）和６５．８７％（ＭｃＡｂ２４＋吡５０ｍｇ／ｋｇ），均高于２组被动免疫转移单抗组的减虫率［２９．８８％（ＭｃＡｂ１４），４０．０１％（Ｍ     

单克隆抗体和吡喹酮协同杀伤日本血吸虫的初步研究

昆明系小白鼠人工感染日本血吸虫尾蚴前２ｈ，４组口服低剂量吡喹酮（吡２０ｍｇ／ｋｇ或吡５０ｍｇ／ｋｇ），并被动免疫转移抗日本血吸虫单抗（ＭｃＡｂ１４或ＭｃＡｂ２４），其减虫率分别为４５．４０％（ＭｃＡｂ１４＋吡２０ｍｇ／ｋｇ）、４４．１５％（ＭｃＡｂ１４＋吡５０ｍｇ／ｋｇ）、４５．７４％（ＭｃＡｂ２４＋吡２０ｍｇ／ｋｇ）和６５．８７％（ＭｃＡｂ２４＋吡５０ｍｇ／ｋｇ），均高于２组被动免疫转移单抗组的减虫率［２９．８８％（ＭｃＡｂ１４）、４０．０１％（ＭｃＡｂ２４）］和２组单剂吡喹酮组的减虫率［１３．８５％（吡２０ｍｇ／ｋｇ）、３１．５０％（吡５０ｍｇ／ｋｇ）］。实验结果提示，单抗协同吡喹酮，可提高减虫率，对预防日本血吸虫病具有一定意义。     

急性肺损伤大鼠白细胞变形性变化及山莨菪碱影响

目的 探讨多形核白细胞（ＰＭＮ）变形性变化在大鼠内毒素性急性肺损伤（ＡＬＩ）中的作用机制及山莨菪碱对ＰＭＮ变形性变化的影响。方法 ４４只大鼠通过静脉注射内毒素（５ｍｇ／ｋｇ）复制大鼠ＡＬＩ模型，每组分为：（１）内毒素１小时组（８只）；（２）内毒素４小时组（８只）；（３）内毒素６小时组（８只）；（４）山莨菪碱治疗组（８只），注射内毒素后，立即静脉注射山莨菪碱５ｍｇ／ｋｇ；（５）正常对照组（１２只），     

Recombinant human relaxin reduces hypoxic pulmonary hypertension in the rat

The fibroproliferative changes in pulmonary artery (PA) remodeling are partially prevented by antifibrotic agents. Relaxin (Rlx), a hormone involved in loosening collagen bundles in ligaments during parturition, has antifibrotic and vasodilator properties that may prevent pulmonary vascular remodeling. In the hypoxia model of pulmonary hypertension, two doses of recombinant human relaxin (rhRlx 24 [high] or 5 [low] mg X 10(-2)/kg d(-1)) were administered subcutaneously continuously for 10d to hypoxic (10% O2) rats. At day 11, right ventricular pressure (Pa X 10(2)) was reduced by rhRlx in a dose-dependent manner (15 +/- 1* control; 28 +/- 1 hypoxia; 23 +/- 1* low; 20+/-1* high; n = 10-14/group, *P < 0.05 vs. hypoxia). High rhRlx ameliorated increased collagen accumulation (mug hydroxyproline/vessel) in main PAs (87 +/- 6) vs. untreated hypoxia (102 +/- 2) (n=5/group, P < 0.05). Infusion of rhRlx had no effect on air-breathing rats, and acute administration did not alter blood pressure in hypoxic rats. Fibroblasts cultured from rat PAs spontaneously expressed collagen and fibronectin, and treatment with TGF-beta increased secretion 26- and 25 X 10(-1)-fold, respectively. Addition of rhRlx to transforming growth factor-beta-stimulated fibroblasts inhibited collagen (37%) and fibronectin (38%) secretion vs. vehicle (n = 4 per group, both P < 0.05). We conclude that rhRlx inhibits the early fibroproliferative response in hypoxic pulmonary hypertension and the mechanism may be due in part to suppression of collagen synthesis.     

肺功能正常吸烟者和慢性阻塞性肺疾病患者肺腺泡动脉炎症特征

目的 研究肺功能正常吸烟者和慢性阻塞性肺疾病(COPD)患者肺腺泡动脉炎症的病理特点。方法 取手术切除的远离周围型肺癌的正常肺组织,分肺功能正常不吸烟组(A组,10例)、肺功能正常吸烟组(B组,13例)、吸烟COPD稳定期组(C组,10例),比较3组肺腺泡动脉病理结构改变、炎性细胞在非肌型动脉(NMA)、部分肌型动脉(PMA)外膜,肌型动脉(MA)内、中、外膜的浸润水平,并分析其与临床指标的相关性。结果 (1)B组(32.7±7.7)、C组(37.4±4.5)较A组(24.4±5.0)MA比例增高,MA内、中膜增厚,C组MA外膜胶原纤维增生,面积明显增大。(2)B组和C组CD+45白细胞、CD3+总T淋巴细胞、CD8+T淋巴细胞在各型肺腺泡动脉表达的范围和程度均较A组增高,以CD8+T淋巴细胞增高为主,炎性细胞浸润以肺腺泡NMA最为明显,在MA以外膜最显著,且C组较B组明显;而CD4+T淋巴细胞、B淋巴细胞、巨噬细胞、中性粒细胞在3组各型肺腺泡动脉浸润程度比较差异均无统计学意义(P值均＞0.05)。(3)CD45+白细胞、CD3+总T淋巴细胞、CD8+T 淋巴细胞在MA的浸润程度与MA管壁厚度、吸烟指数呈正相关,与第1秒用力呼气容积占预计值百分比呈负相关,CD3+总T淋巴细胞、CD8+T淋巴细胞浸润程度与BODE指数呈正相关,CD8+T淋巴细胞浸润程度与6 min步行距离呈负相关。结论 肺功能正常吸烟者和COPD患者均已出现以CD8+T 淋巴细胞浸润为特征的同性质炎症反应,炎症累及各型肺腺泡动脉,肺动脉炎症是影响COPD临床病程发展的重要因素之一。     

L-精氨酸对低氧性肺动脉高压大鼠肺动脉平滑肌细胞凋亡的影响

目的 探讨L-精氨酸(L-Arg)对低氧性肺动脉高压大鼠不同节段肺动脉平滑肌细胞凋亡的影响。方法 将Wistar大鼠(n=19)随机分为对照组(n=7)、低氧组(n=6)及低氧 L-Arg组(n=6)。经右心导管法测定各组大鼠肺动脉压力和右室(RV)/左室 室间隔(LV S)比值,以分光光度法间接测定血浆一氧化氮(NO)含量,通过TUNEL法检测各组大鼠不同节段的肺动脉平滑肌细胞凋亡数目,并计算肺动脉平滑肌细胞凋亡数目与肺动脉平滑肌细胞数目比值。结果 低氧组大鼠肺动脉平均压(PAMP)显著高于对照组[(2.71±0.29)kPa vs(2.05±0.14)kPa,P<0.01],低氧 L-Arg组大鼠的PAMP显著低于低氧组[(2.23±0.18)kPa vs(2.71±0.29)kPa,P<0.05];低氧组大鼠RV/(LV S)比值显著高于对照组[(0.42±0.03)kPa vs(0.30±0.05)kPa,P<0.01],低氧 L-Arg组大鼠RV/(LV S)比值显著低于低氧组[(0.36±0.02)kPa vs(0.42±0.03)kPa,P<0.01];低氧组大鼠血浆NO含量明显低于对照组[(3.54±0.47)μmol/L vs(4.79±0.17)μmol/L,P<0.05],低氧 L-Arg组大鼠血浆NO含量显著高于低氧组[(5.21±0.26)μmol/L vs(3.54±0.47)μmol/L,P<0.01];低氧组大鼠与终末细支气管伴行的肺动脉和与呼吸细支气管伴行的肺动脉平滑肌细胞凋亡数目与平滑肌细胞数目比值明显低于对照组[(0.051±0.016     

Reduction of chronic hypoxic pulmonary hypertension in the rat by an inhibitor of collagen production

Chronic hypoxic pulmonary hypertension in the rat is associated with increased collagen and elastin in the pulmonary artery. We investigated whether excess vascular collagen contributes to chronic hypoxic pulmonary hypertension by administering the proline analogue cis-4-hydroxy-L-proline (cHyp), an agent relatively specific for inhibiting collagen production, to rats exposed to chronic hypoxia. Sprague-Dawley rats (weighting 200 g) were exposed to air or hypoxia (10% O2-90% N2) for 3 wk. Groups studied were: air-exposed injected with saline, air-exposed injected with cHyp, hypoxic injected with saline, and hypoxic injected with cHyp. At the end of 3 wk, we measured mean right ventricular pressure (RVP) of animals breathing room air and hydroxyproline and desmosine contents of the main pulmonary artery trunk. Hypoxia increased RVP from 13 +/- 1 to 27 +/- 1 mm Hg (p less than 0.05); cHyp partially prevented this increase since RVP was 17 +/- 1 mm Hg (p less than 0.05). There was no effect of cHyp on cardiac output. Hypoxia increased collagen from 0.9 +/- 0.1 to 2.0 +/- 0.3 mg/artery (p less than 0.05); cHyp completely prevented this increase since collagen was 1.0 +/- 0.2 mg/artery (p less than 0.05). Hypoxia increased elastin from 1.1 +/- 0.1 to 2.4 +/- 0.2 mg/artery (p less than 0.05); cHyp had no apparent effect since elastin was 2.1 +/- 0.1 mg/artery. Also, cHyp did not affect RVP or vascular collagen or elastin in air-breathing animals. The cHyp treatment prevented luminal narrowing and thickening of arteriolar walls by hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)     

碱性成纤维细胞生长因子在低氧性肺动脉高压大鼠肺内表达…

OBJECTIVE: To evaluate the role of bFGF in the development of hypoxic pulmonary hypertension. METHOD: Rat models with chronic hypoxia induced pulmonary hypertension were established, the pulmonary hemodynamics were measured and the pulmonary arterioles change were studied with morphometric analysis under light microscopes, immunohistochemical staining with monoclonal antibody against human recombinant bFGF was performed in the paraffin section of rat lung. RESULT: (1) The mean pulmonary artery pressure (mPAP), and the ratio of the thickness of pulmonary arteriolar wall to external diameter of pulmonary arterioles (MT%) were 3.96 +/- 0.47 kPa and 33.8% +/- 3.5% in rats exposed to hypoxia for 3 weeks respectively, both were significant higher than those in normal control group, P < 0.01. (2) The positive staining for bFGF in the wall of pulmonary arterioles in hypoxic rats was stronger than that of control group (P < 0.01), there was a statistical relationship between increase of staining for bFGF and MT% in rats exposed to hypoxia. CONCLUSION: (1) Hypoxia can induce formation of pulmonary hypertension and structual remodeling of pulmonary arterioles. (2) bFGF may modulate the structure remodeling of pulmonary arterioles in chronic hypoxic pulmonary hypertension.     

蛋白激酶C激活剂对缺氧性动脉高压大鼠离体肺动脉环反应性？…

观察缺氧性动脉高压大鼠离体肺动脉环对蛋白激酶激活剂豆蔻酸佛波酰乙酰的反应性变化。方法取缺氧２周并已经形成肺动脉高压的大鼠和正常对照组大鼠肺动脉环,观察在离体情况下对０．５μｍｏｌ／ＬＰＭＡ的最大张力反应及达到二分之一最大张力所需的时间,并描绘两肺动脉环对０．０１－１０．０μｍｏｌ／ＬＰＭＡ的浓度－反应曲线。     

PDGF在高原性肺动脉高压大鼠肺动脉中的表达及波生坦对其表达的影响

目的:观察低氧性肺血管重建(HPSR)中肺动脉平滑肌增生性改变,探讨波生坦(BST)对高原性肺动脉高压(HAEPH)的逆转作用及对HAEPH大鼠肺动脉血小板源性生长因子(PDGF)表达的影响。方法:采用全自动调节的低压低氧舱模拟海拔5 000~5 500 m高度的气压环境(大气压约50 kPa),建立慢性HAEPH大鼠模型。将40只SD大鼠随机分为4组:对照组、模型组、安慰剂组和BST组,每组各10只。对照组常压常氧下饲养6周,其他3组均置于低压低氧仓中进行间断低氧(8 h/d),并分别饲养3周、6周、6周。自第4周起,安慰剂组和BST组大鼠在入仓前分别给予生理盐水(2 ml)和BST(100 mg/kg)灌胃。6周后取肺组织石蜡包埋,连续切片后,观察肺血管形态学变化。用免疫组织化学染色法对各组大鼠肺动脉中PDGF的表达进行定位及半定量分析。结果:①安慰剂组大鼠的肺动脉管壁增厚、管腔狭窄,BST组大鼠的肺动脉管壁厚度及管腔恢复至正常组状态。②各组大鼠肺动脉均有PDGF表达,随低氧时间的延长,PDGF的表达逐渐增加,BST组PDGF的表达与正常组比较无统计学差异。结论:①BST可有效地逆转HPSR,提示BST对HAEPH具有治疗作用。②BST对HAEPH大鼠肺动脉中PDGF的表达具有抑制作用。     

Collagen and elastin metabolism in hypertensive pulmonary arteries of rats

We evaluated the processes controlling the accumulation of collagen and elastin in main pulmonary arteries of rats during an episode of hypoxic pulmonary hypertension. Explant cultures of main pulmonary arteries were incubated with [3H]proline to measure collagen and protein synthesis and percent collagen synthesis. Elastin synthesis was measured by [14C]valine incorporation into insoluble elastin. Relative collagen synthesis increased twofold (from 1.1 +/- 0.2 x 10(3) to 2.0 +/- 1.0 x 10(3) disintegrations per minute [14C]hydroxyproline/vessel/hr/mg protein), relative collagen synthesis doubled (from 2% to 4-5% of total protein synthesis), and elastin synthesis increased ninefold (from 0.4 +/- 0.2 x 10(4) to 3.6 +/- 0.6 x 10(4) dpm [14C]valine/vessel/hr/mg protein) in early hypertension. The level of pro alpha l(I) collagen RNA paralleled the relative collagen synthetic rate during the study period. Within 7 days of recovery from hypoxia, collagen and elastin contents were normal. We conclude that collagen and elastin in main pulmonary arteries are synthesized rapidly during an episode of hypoxic pulmonary hypertension and that collagen and elastin are rapidly removed from the hypertensive vessel during normoxic recovery.     

新型内源性气体信号分子硫化氢对低氧性肺血管胶原重塑的影响

目的研究大鼠低氧性肺血管重塑时硫化氢(H2S)对Ⅰ、Ⅲ型胶原蛋白在肺血管壁异常堆积的调节作用,进一步探讨H2S缓解低氧性肺血管重塑的作用机制。方法19只雄性Wistar大鼠随机分为对照组、低氧组、低氧+硫氢化钠(NaHS)组。低氧组和低氧+NaHS组大鼠共低氧21d,低氧+NaHS组大鼠每天低氧前腹腔注射H2S供体NaHS。低氧结束后,测定肺动脉平均压(mPAP),称重右心室(RV)和左心室+室间隔(LV+SP),计算RV/(LV+SP)。亚甲蓝分光光度法测定血浆中H2S含量。免疫组化染色检测Ⅰ、Ⅲ型胶原蛋白,原位杂交检测Ⅰ、Ⅲ型前胶原mRNA在肺血管壁表达。结果(1)与对照组相比,低氧组大鼠mPAP升高46%,RV/(LV+SP)增加41%,血浆H2S含量下降36%(P均<0·01);与低氧组相比,低氧+NaHS组大鼠的mPAP降低31%,RV/(LV+SP)减少24%,血浆H2S含量升高65%(P均<0·01)。(2)各组大鼠肺小型、中型肌性动脉中Ⅰ型胶原蛋白表达的比较:低氧组较对照组分别增加81%、62%(P<0·01);低氧+NaHS组较低氧组分别减少了32%、18%(P<0·01)。(3)各组大鼠肺小型、中型肌性动脉中Ⅰ型前胶原mRNA表达的比较:低氧组较对照组分别增加49%、68%(P<0·01);低氧+NaHS组较低氧组分别减少了31%、33%(P<0·01)。(4)各组大鼠肺小型肌性动脉中Ⅲ型胶原蛋白表达的比较:低氧组较对照组增加84%(P<0·01);低氧+NaHS组较低氧组减少了37%(P<0·01)。低氧组大鼠的肺中型肌性动脉中Ⅲ型胶原蛋白表达较对照组增加38%(P<0·01);但是与低氧+NaHS组相比无明显变化(P>0·05)。(5)各组大鼠肺小型、中型肌性动脉中Ⅲ型前胶原mRNA表达的比较:低氧组较对照组分别增加53%、17%(P<0·01);低氧+NaHS组较低氧组分别减少了45%、33%(P<0·01)。结论在大鼠低氧性肺血管胶原重塑时,H2S能够抑制Ⅰ、Ⅲ型胶原蛋白及其mRNA在肺血管壁的表达,此作用可能是其缓解低氧性肺血管重塑的作用机制之一。     

ATP钾通道开放剂对大鼠慢性低氧性肺动脉高压的作用

目的：研究ATP敏感性钾通道开放剂左旋克罗卡琳（levcromakalim)和克罗卡啉（cromakalim)对慢性低氧大鼠肺动脉平滑肌细胞钾通道（KATP)和低氧性肺动脉高压的作用。方法：90只Wistar大鼠随机分为正常对照组（15只）和低氧组（75只）。应用膜片钳技术，在对称性高钾溶液中，将急性分离的大鼠肺动脉平滑肌细胞的内面向外式膜片上，分离出ATP敏感性KATP电流。应用右心插管技术，测定给药前、后大鼠平均肺动脉压（mPAP)。结果：慢性低氧3周大鼠肺动脉平滑肌细胞KATP通道活性与正常组大鼠比较无明显变化。但钾通道开放剂levcromakalim和cromakalim可明显激活慢性低氧大鼠肺动脉平滑肌细胞KATP电流。给低氧大鼠静脉注射levcromakalim和cromakalim，可对其mPAP产生剂量依赖性的降压作用，而对平均体动脉压也有一定的降低作用。结论：虽然KATP可能没有直接参与大鼠慢性低氧性肺动脉高压的产生，但levcromakalim和cromakalim可通过激活KATP通道而拮抗低氧对其它钾通道的抑制作用，levcromakalim和cromakalim可降低慢性缺氧大鼠低氧性肺动脉高压。