内源性一氧化氮在哮喘大鼠气道高反应性中的作用

目的　利用一氧化氮合成前体Ｌ精氨酸（ＬＡｒｇ） 和一氧化氮合酶抑制剂亚硝基Ｌ精氨酸甲酯（ＬＮＡＭＥ）研究内源性一氧化氮在哮喘大鼠气道高反应性中的作用,探讨支气管哮喘的发病机制。方法　用卵白蛋白作为致敏原制备哮喘大鼠模型,建立大鼠离体气管环张力的测定方法,并用ＬＡｒｇ、ＬＮＡＭＥ和ＬＡｒｇ＋ ＬＮＡＭＥ孵育离体气管环,观察气管环乙酰胆碱浓度反应曲线和最大收缩反应的变化,同时观察去上皮对哮喘大鼠气道反应性的影响。结果　哮喘大鼠（１０ 只） 离体气管环经ＬＮＡＭＥ１０５ ｍｏｌ／Ｌ孵育后对乙酰胆碱的最大收缩反应从孵育前（１２４±３９） ｍｇ 上升到（１８７ ±５３） ｍｇ,孵育前、后最大收缩反应比较差异具有显著性（ Ｐ＜ ０．０１）,浓度反应曲线上移,而ＬＡｒｇ 可以逆转ＬＮＡＭＥ的作用,单用ＬＡｒｇ ２×１０５ ｍｏｌ／Ｌ和ＬＡｒｇ１０３ ｍｏｌ／Ｌ孵育气管环,对哮喘大鼠气管环的最大收缩反应和浓度反应曲线与对照组比较,差异无显著性（ Ｐ＞ ０．０５） 。去上皮哮喘大鼠气管环的反应性与上皮完整气管环比较差异有显著性（ Ｐ＜ ０．００５） ,而ＬＡｒｇ、ＬＮＡＭＥ＋ ＬＡｒｇ 和ＬＮＡＭＥ孵育去上     

静止期溃疡性结肠炎肠粘膜过量一氧化氮的产生及其意义

应用ＮＡＤＰＨ－黄递酶组织化学染色方法和巨噬细胞免疫组织化学ＡＢＣ法，对１７例静止期溃疡性结肠炎患者肠粘膜进行一氧化氮合成酶活性测定。结果显示：静止期ＵＣ患者肠粘膜ＮＯＳ阳性颗粒率及巨噬细胞数均显著高于健康对照组表明：静止期ＵＣ患者肠粘膜中的ＮＯＳ活性增高，ＮＯ产生量增加，巨噬细胞可能是产生过量ＮＯ的主要来源ＮＯ的过量存在有可能是 发的原因之一。     

一氧化氮合成酶在支气管哮喘中作用的实验研究

为探讨一氧化氮合成酶（ｎｉｔｒｉｃｏｘｉｄｅｓｙｎｔｈａｓｅ，ＮＯＳ）在实验性大鼠支气管哮喘中的作用，采用３Ｈ－Ｌ－精氨酸转化实验检测鼠肺组织ＮＯＳ活性［１］及还原型辅酶Ⅱ黄递酶（ＮＡＤＰＨ－ｄ）组化染色［２］。结果表明，哮喘组的诱生型ＮＯＳ（ｉＮＯＳ）活性增加１５２．３９％～２４９．４０％，而原生型ＮＯＳ（ｃＮＯＳ）活性则降低６１．８１％～６４．８４％（Ｐ＜０．０５）；致敏组ｉＮＯＳ活性较对照组增加６７．８１％（Ｐ＜０．０５），ｃＮＯＳ活性则无甚改变。ＮＡＤＰＨ－ｄ组化染色显示，哮喘组的气管、细支气管上皮均有整片深着色。哮喘时ｉＮＯＳ活性常呈上调，而ｃＮＯＳ则下调，且ｉＮＯＳ的上调作用尤早于ｃＮＯＳ的下调。提示哮喘时的气道炎症性改变，发生于气道平滑肌收缩及内皮损伤之前。     

硝酸甘油对哮喘患者一氧化氮内皮素的影响及机制

目的　了解哮喘患者肺泡巨噬细胞（ＡＭ） 、支气管上皮细胞（ＢＥＣ） 源性一氧化氮（ＮＯ）、内皮素（ＥＴ）的分泌状态及硝酸甘油（ＮＴＧ）对哮喘患者ＡＭ、ＢＥＣ产生ＮＯ、ＥＴ的影响及机制。方法　分离纯化了１５ 例轻、中度哮喘发作期患者、７ 名健康受试者ＡＭ、ＢＥＣ,并分为哮喘未干预组、哮喘ＮＴＧ干预组和健康对照组,用放射免疫法和镀铜镉还原法分别测定ＡＭ、ＢＥＣ培养４８ 小时上清液中ＥＴ、ＮＯ·２／ＮＯ·３ 浓度,用原位杂交的方法检测ＡＭ、ＢＥＣｉＮＯＳｍＲＮＡ、ＥＴｍＲＮＡ 的表达。结果　（１） 健康受试者ＡＭ、ＢＥＣ分泌少量ＮＯ和ＥＴ及少量ｉＮＯＳｍＲＮＡ 、ＥＴｍＲＮＡ表达;（２）哮喘患者ＡＭ、ＢＥＣ源性ＮＯ、ＥＴ水平及ＡＭ、ＢＥＣｉＮＯＳｍＲＮＡ、ＥＴｍＲＮＡ表达与各组比较差异有显著性（ Ｐ均＜ ０－０５）;（３）ＮＴＧ 促进哮喘患者ＡＭ、ＢＥＣ源性ＮＯ产生（ Ｐ均＜０－０５）,明显抑制ＥＴ产生和ＥＴｍＲＮＡ 的表达,与对照组比较差异均无显著性（ Ｐ均＞ ０－０５） ,ＮＴＧ同时抑制哮喘患者ＡＭ、ＢＥＣｉＮＯＳｍＲＮＡ的表达,与健康对照组、哮喘未干预组比较差异有显著性（Ｐ均＜０－０５） ;（４） 除哮喘ＮＴＧ     

图像定量分析肝硬化大鼠肠壁内一氧化氮合成酶的分布

目的：探讨一氧化氮（ＮＯ）在肝硬化门脉高压性肠道功能异常中可能的作用。方法：用依赖还原性辅酶ＩＩ硫辛酰胺脱氢酶（ＮＡＤＰＨ－ｄｉａｐｈｏｒａｓｅ，ＮＡＤＰＨ－ｄ）组织化学方法对正常对正常及肝硬化大鼠结肠与回肠内一氧化氮合成酶（ＮＯＳ）进行定位研究，并用图像测量方法对两组大鼠肠壁内ＮＯＳ进行定量分析，结果：肝硬化大鼠结肠及回肠壁内ＮＯＳ阳性纤维及胞体比正常组明显增多，染色增强；两组的面积，灰度及光密     

一氧化氮合酶抑制剂对博莱霉素所致肺损伤的影响

目的观察一氧化氮合酶（ＮＯＳ）活性在博莱霉素（ＢＬＭ）所致大鼠肺间质纤维化过程中的动态变化,探讨ＮＯＳ抑制剂氨基胍（ＡＧ）对大鼠肺纤维化模型的影响及其作用机制。方法观察各组动物肺脏病理组织学改变和肺匀浆中ＮＯＳ活性、丙二醛（ＭＤＡ）以及肿瘤坏死因子α（ＴＮＦα）含量的变化。结果肺匀浆中ＮＯＳ活性在气管灌注ＢＬＭ后迅速上升,第７天达高峰（与对照组相比,Ｐ＜０．０１）,于第２８天基本恢复正常。ＡＧ能显著降低肺匀浆中ＮＯＳ活性,显著延缓、减轻肺泡炎。结论一氧化氮（ＮＯ）在肺间质纤维化的发生发展特别是肺泡炎阶段起着重要作用。     

内皮素和一氧化氮平衡在哮喘犬发病机制中的作用

目的 探讨内皮素（ＥＴ）和一氧化氮（ＮＯ）平衡失调在支气管哮喘（简称哮喘）发病机制中的作用。方法 吸入猪蛔虫抗原复制过敏性哮喘犬模型，随机将实验动物分为五组，即对照组（Ａ组，６只），哮喘组（Ｂ组，６只）生理盐水＋哮喘组（Ｃ组，６只）Ｎ＾Ｇ－单甲基左旋精氨酸（Ｌ－ＮＭＭＡ）＋哮喘组（Ｄ组，６只）和左旋精氨本－ａｒｇ）＋哮喘组（Ｅ组，６只），观察了ＥＴ－１和ＮＯ对犬气道平滑肌的影响。结果 ＥＴ－１使呼     

猪苓多糖对小鼠腹腔巨噬细胞一氧化氮生成的影响及其机理

目的 探讨猪苓多糖（ＰＰＳ）的免疫调节和免疫的作用机理。方法 观察ＰＰＳ对小鼠腹腔巨噬细胞一氧化氮（ＮＯ）生成和诱导型一氧化氮合酶（ｉＮＯＳ）的影响。结果 ＰＰＳ对小鼠腹腔巨噬细胞ＮＯ生成具有明显的促进作用，呈剂量依赖依赖关系，并与干扰素－γ（ＩＦＮ－γ）具有协同促进作用。这一促进作用能被ＲＮＡ转录抑制剂放线菌素Ｄ、蛋白质合成抑制剂放线菌酮和ｉＮＯＳ抑制剂Ｌ－ＮＭＡ所抑制。结论 ＰＰＳ可能单独或与     

高血压病人血小板L—精氨酸／一氧化氮系统的改变

目的原发性高血压（ＥＨ）病人（２３例）与健康成年人（１４）例作对照，观察高血压时血小板（Ｐｔ）左旋精氨酸（Ｌ－Ａｒｇ）－一氧化氮（ＮＯ）系统的改变及Ｌ－Ａｒｇ转运的特征。方法微盘测定法测定血小板孵育液中亚硝酸盐（ＮＯ２－）的含量来反映ＮＯ产生量、ＡＤＰ刺激下ＮＯ的产生量；采用张新波等建立的一氧化氮合酶（ＮＯＳ）测定改良法测定血小板ＮＯＳ活性；放射性同位素标记测定血小板３Ｈ－Ｌ－Ａｒｇ转运的动力学特征。结果ＥＨ患者Ｐｔ的ＮＯ产生量及ＮＯＳ活性较对照组明显降低（Ｐ＜０．０１），用ＡＤＰ刺激后，ＥＨ患者Ｐｔ的ＮＯ增加量仅为正常对照组增加量的６０％，其Ｌ－Ａｒｇ转运能力亦显著低于正常人（各浓度点Ｐ均＜０．０１）。最大转运速率（Ｖｍａｘ）仅为正常人的７９％（Ｐ＜０．０１），而米氏常数（Ｋｍ）则无明显改变（Ｐ＞０．０５）。结论高血压时Ｐｔ的Ｌ－Ａｒｇ－ＮＯ系统存在明显异常，提示对ＥＨ患者，在降压的同时，联合应用改善Ｌ－Ａｒｇ－ＮＯ系统的药物，对预防和治疗高血压减少并发症可能会有更好的效果。     

吸入L—精氨酸对哮喘豚鼠气道反应性的影响

吸入Ｌ－精氨酸对哮喘豚鼠气道反应性的影响张建勇朱惠如钱梓文一氧化氮（ＮＯ）是一种新的信使分子，参与气道反应性的调节，Ｌ－精氨酸（Ｌ－Ａｒｇ）是体内ＮＯ合成的前体。本研究通过测定肺阻力（ＲＬ）与肺顺应性（ＣＬ），旨在观察吸入Ｌ－Ａｒｇ对清醒状态哮喘豚鼠...     

过氧亚硝基阴离子在哮喘豚鼠气道高反应性中的作用

目的 探讨哮喘豚鼠内过氧亚硝基阴离子（ＯＮＮＯＯ＾－）的生成及其在哮喘气道高反应性形成中的作用。方法 １８只哮喘豚鼠模型随机分为３组：（１）哮喘组（６只）：用１０％卵蛋白１ｍｌ腹腔注射液致敏,２周后用１％卵蛋白超声雾化吸入复制豚鼠哮喘模型。（２）哮喘加氨基胍（ＡＧ）组（６只）：该喘同哮喘组,在每次诱喘前１ｈ腹腔注射ＡＧ１０ｍｇ／ｋｇ。（３）正常对照组（６只）：用生理盐水代替诱喘剂。每组哮喘豚鼠均用     

Effect of ascorbic acid on airway responsiveness in ovalbumin sensitized guinea pigs

OBJECTIVE: The most important pathological feature of asthma is airway inflammation, which results in airway hyper-responsiveness. We hypothesized that excessive oxidation is likely to contribute to airway inflammation in asthma. The aim of this study was to evaluate the effects of both acute exposure and a 30-day administration of ascorbic acid (AA), which has an antioxidant effect, on airway responsiveness in sensitized guinea pigs. METHODOLOGY: Guinea pigs sensitized to ovalbumin (OA), were given drinking water without AA (group 2) or with AA (group 3). The responses of tracheal chains of control animals (group 1) and both groups of sensitized guinea pigs (n = 10, for all groups) to cumulative concentrations of methacholine were measured, and the effective concentrations of methacholine causing 50% of maximum response (EC50 M) were obtained. The response of tracheal chains to 0.1% OA, relative to contraction obtained with 10 micro mol/L methacholine, was also measured. The tracheal responses to methacholine and OA were measured on tissues both incubated and not incubated with AA. RESULTS: The tracheal responses of group 2 tissues were significantly greater than those of groups 1 and 3 to both OA and methacholine (P < 0.05). There were no significant differences in tracheal responses to OA and methacholine between groups 1 and 3. Acute incubation of tissues caused a reduction of tracheal response to methacholine in all groups, but this was only significantly differ-ent for group 3 (P < 0.05). Acute incubation of tissues did not change tracheal response to OA significantly. CONCLUSION: These results showed that although short-term administration of AA had no major effect on tracheal responsiveness among sensitized animals, 30-day administration of AA could lead to a decrease in airway responsiveness of sensitized guinea pigs to both OA and methacholine.     

Effects of verapamil on histamine-and carbachol-induced contraction of pulmonary tissues in vitro

It has been hypothesized that calcium antagonists may be useful in the management of airway hyperreactivity. In these studies, we evaluated the effects of verapamil on guinea pig tracheal spirals and parenchymal lung strips in vitro. Preincubation of both tissues with verapamil caused concentration-dependent inhibition of contraction with significant effects noted at a 10 micromolar concentration. At this concentration of verapamil, approximately fivefold greater concentrations of either histamine or carbachol were required to produce contraction of tracheal spirals; and 21-fold greater concentrations of histamine and 630-fold greater concentrations of carbachol were required to contract parenchymal strips. We also assessed the ability of verapamil to reverse contraction. Significant reversal of both histamine- and carbachol induced contraction was observed with concentrations of 3 micromolar verapamil and contraction was nearly abolished with a 100 micromolar concentration. These data demonstrate that verapamil can both inhibit airway contraction and reverse contraction once it is present and further suggest that verapamil or other calcium antagonists may prove useful in the management of airway hyperreactivity.     

母牛分支杆菌菌苗对哮喘豚鼠气道收缩和炎症反应的影响

目的　观察母牛分支杆菌菌苗 (微卡 )对致敏豚鼠抗原攻击后肺功能、气道炎症 ,离体气管平滑肌高反应性的影响。方法　 71只豚鼠采用卵蛋白致敏形成豚鼠哮喘模型 ,测定肺阻力 (RL)和动态肺顺应性 (Cdyn)、支气管肺泡灌洗液 (BALF)中的炎症细胞以及卡巴胆碱 (carbachol)诱导的离体气管平滑肌高反应性。结果　微卡单次肌肉注射预处理呈量效关系抑制致敏豚鼠抗原攻击后引起哮喘速发相反应。微卡 2 .5 μg组RL(1～ 15min)平均增值为 4 6 4 % ,7 5 μg组为 2 9 6 % ,2 2 5 μg组为2 0 8% ,而模型组为 95 3% ,用药各组与模型组比较 ,差异有显著性 (P <0 0 5、<0 0 1) ;微卡 2 5 μg组Cdyn(1～ 15min)平均下降值为 2 6 8% ,7 5 μg组为 2 3 5 % ,2 2 5 μg组为 2 1 5 % ,而模型组为 38 7% ,微卡用药各组与模型组比较 ,差异有显著性 (P <0 0 5 )。微卡单次肌肉注射也能抑制哮喘的迟发相 ,微卡 2 5 μg组BALF中的白细胞总数为 (16 2± 3 2 )× 10 8/L ,微卡 7 5 μg组为 (14 6± 3 4 )× 10 8/L ,微卡2 2 5 μg组为 (15 4± 2 5 )× 10 8/L ,而模型组为 (2 2 3± 2 2 )× 10 8/L ,微卡用药各组与模型组比较 ,差异有显著性 (P <0 0 1、<0 0 0 1) ;微卡 2 5 μg组BALF中的嗜酸性粒细胞数为 (11     

Leukotriene E4-induced airway hyperresponsiveness of guinea pig tracheal smooth muscle to histamine and evidence for three separate sulfidopeptide leukotriene receptors.

Bronchial hyperresponsiveness to contractile agonists and nonspecific irritants is a characteristic feature of bronchial asthma. The mechanisms causing this hyperirritability are unknown. The existence of separate receptors for leukotrienes C4 and D4 (LTC4 and LTD4) has been demonstrated previously by physiologic and radioligand binding studies. The rank order of potency of the sulfidopeptide leukotrienes for contracting tracheal spirals [leukotriene E4 (LTE4) greater than LTD4 = LTC4] is different from that for contracting parenchymal strips (LTD4 greater than LTE4 greater than LTC4), thereby suggesting the existence of a separate receptor for LTE4. We now report that LTE4, the most stable of the leukotrienes comprising slow reacting substance of anaphylaxis, enhances the contractile response of guinea pig tracheal spirals but not of parenchymal strips to histamine in a time- and dose-dependent fashion. The ability of LTE4 to increase histamine responsiveness occurred after removal of the free agonist and recovery of the tissues to baseline tensions and was not produced by leukotrienes C4 and D4, which elicited the same magnitude of contraction of tracheal smooth muscle as LTE4. These findings suggest that LTE4-induced airway hyperirritability is not mediated by the contractile response per se and may be mediated through a receptor distinct from those for leukotrienes C4 and D4.     

一氧化氮及其合酶在哮喘发病机制中的作用

探讨一氧化氮及其合酶在哮喘发病机制中的作用。方法 采用哮喘豚鼠模型，将豚鼠分为４组；１．哮喘组，用１０％卵白蛋白腹腔注射１ｍｌ致敏，２周后用１％卵白蛋白超声雾化吸入致其哮喘发作．２；肾上腺皮质激素预防组；诱喘同哮喘组，在每次诱喘前腹腔滴注地塞米松０．５ｍｇ／ｋｇ。３．硝基精氨酸甲酯预防组；诱喘同哮喘组，每次诱喘产腹腔注射ＬＮＮＡ０．４ｍｇ／ｋｇ。４．正常对照组；用生理盐水代替诱喘剂。每组分别测定其     

A mechanism of paraquat toxicity involving nitric oxide synthase

Paraquat (PQ) is a well described pneumotoxicant that produces toxicity by redox cycling with cellular diaphorases, thereby elevating intracellular levels of superoxide (O-(2)). NO synthase (NOS) has been shown to participate in PQ-induced lung injury. Current theory holds that NO reacts with O-(2) generated by PQ to produce the toxin peroxynitrite. We asked whether NOS might alternatively function as a PQ diaphorase and reexamined the question of whether NO/O-(2) reactions were toxic or protective. Here, we show that: (i) neuronal NOS has PQ diaphorase activity that inversely correlates with NO formation; (ii) PQ-induced endothelial cell toxicity is attenuated by inhibitors of NOS that prevent NADPH oxidation, but is not attenuated by those that do not; (iii) PQ inhibits endothelium-derived, but not NO-induced, relaxations of aortic rings; and (iv) PQ-induced cytotoxicity is potentiated in cytokine-activated macrophages in a manner that correlates with its ability to block NO formation. These data indicate that NOS is a PQ diaphorase and that toxicity of such redox-active compounds involves a loss of NO-related activity.     

Relationship between nonspecific airway hyperreactivity and antigen-induced contraction in an allergic animal model in vitro

Tracheal strips from actively sensitized guinea pigs exhibited an enhanced responsiveness (greater maximal effects; Emax) and sensitivity (smaller effective concentration 50%; pD2) to CaCl2 (in K(+)-depolarized tissues), KCl and histamine compared with that of strips from nonsensitized animals. A significant correlation was found between the magnitude of the contraction produced by bovine serum albumin (1 mg/ml) and the Emax and pD2 values of CaCl2, KCl and histamine in tracheal strips from sensitized guinea pigs. This indicates that specific and nonspecific challenges correlate in sensitized guinea pig trachea.