加速度致大鼠脑缺血急性期血浆一氧化氮、一氧化氮合酶和白细胞介素6的含量变化

目的：观察实施加速度作用后造成大鼠脑缺血，在急性期血浆中的一氧化氮、一氧化氮合酶(NOS）和白细胞介素-6(IL-6）的含量变化，探讨加速度对机体引起的继发性脑损伤程度及机制。方法：30只雄性健康Wistar大鼠，随机分为3组，分别施加+1Gz(正加速度)、高+Gz和正、负加速度(&;#177;Gz)的交替作用，并把被施加+1Gz加速度的大鼠作为对照组。于加速度作用后即刻麻醉，腹主动脉采血。分别测定各组大鼠血浆中一氧化氮、NOS和IL-6的含量。结果：一氧化氮含量：&;#177;Gz交替组[(60．4&;#177;6．6)μmol／L]与高+Gz组[(50．3&;#177;2．2)μmol／L]比较，t=16．5250；高+Gz组与对照组[(35．9&;#177;33)μmol／L1比较，t=27．9397；&;#177;Gz交替组与对照组比较，t=50．0324，P均&;lt;0.01 NOS活性：&;#177;Gz交替组[(890&;#177;73)μmol／(s&;#183;L)]与高+Gz组[(791&;#177;60）μmol／(s&;#183;L)]比较，t=3．3147；高+Gz组与对照组[（332&;#177;27）μmol／(s&;#183;L)]比较，t=23．4389；&;#177;Gz组与对照组比较，t=25．9615，P均&;lt;0．01；L-6含量：&;#177;Gz交替组[(132&;#177;18）ng／L]与高+Gz组[（106&;#177;15)ng／L]比较，t=19．6748；高+Gz组与对照组[（71&;#177;10）ng／L比较，t=249296；&;#177;Gz组与对照组比较，t=481645．P均&;lt;0。01 结论：正、负加速度交替和单纯高正加速度作用均可使血浆中的一氧化氮、NOS和IL-6的含量增加明显，且正、负加速度交替对机体的作用更明显，损伤程度更严重。     

电针对癫痫大鼠脑组织及肝脏的一氧化氮和一氧化氮合酶含量的影响

目的:探讨电针对癫痫大鼠脑组织和肝组织中一氧化氮,一氧化氮合酶(nitricoxidesyntheses,NOS)的影响,以及电针治疗癫痫的可能机制。方法∶实验于2004-03/10在南京中医药大学第二临床医学院实验室完成。选择SD大鼠40只,随机分成为正常组、模型组、电针组、假针刺组,每组10只。采用比色法测定对癫痫造模大鼠的一氧化氮,NOS和一氧化氮/NOS比值进行随机对照分析性研究。结果∶模型组脑一氧化氮犤(19.76±2.66)μmol/L犦,NOS犤(498.8±94.7)nkat/g犦和一氧化氮/NOS比值(1.38±0.46)明显高于正常组(P<0.05),电针组脑一氧化氮犤(6.04±3.52)μmol/L犦,NOS犤(203.9±102.2)nkat/g犦和一氧化氮/NOS比值(1.00±0.57)明显低于模型组(P<0.05),假针刺组一氧化氮,NOS和一氧化氮/NOS含量不明显变化。肝组织中各项因子变化与脑组织中变化一致。结论∶电针对癫痫大鼠的一氧化氮,NOS和一氧化氮/NOS有显著的抑制调节作用。这可能是电针治疗癫痫临床取得疗效的重要机制之一。     

捕食应激对大鼠海马一氧化氮及神经型一氧化氮合酶的影响

目的探讨一氧化氮(NO)在创伤后应激障碍(PTSD)样行为异常大鼠的变化规律,以进一步揭示PTSD的神经生物学机制。方法将144只Wistar大鼠随机分组为捕食应激组(n=72)及正常对照组(n=72),在大鼠捕食应激PTSD动物模型基础上,动态检测大鼠海马、额叶皮层组织匀浆NO、一氧化氮合酶(NOS)含量及神经元型NOS(nNOS)表达。结果应激大鼠海马NO含量于捕食应激后即刻明显高于对照组犤(2.8±0.8)μmol/g,F=23.112,P=0.000犦,12h达高峰(3.9±1.1)μmol/g,与对照组比较,F=56.616,P=0.000;与同组其他时相比较,F=14.917,P<0.05,24h时仍明显增多犤(2.6±0.7)μmol/g,F=23.094,P=0.000犦;海马nNOS表达亦同步增高(应激后即刻,12及24h,F=14.228,21.772,18.500,P<0.01),而海马总NOS活性仅在应激后12h内增高犤应激后即刻及12hNOS分别为(9.8±2.5)mmol/(s·kg),F=32.812,P=0.000及(10.2±2.7)mmol/(s·kg),F=31.395,P=0.000犦。结论严重心理/生理应激所致海马nNOS持续性高表达与NO释放明显增多,在实验大鼠持续性PTSD样行为异常中可能有重要作用。     

银杏叶片对高原人体运动后一氧化氮及一氧化氮合酶的影响

目的:缺氧会对机体造成多种损伤,探讨银杏叶片、酪氨酸冲剂和红景天对高原人体力竭运动一氧化氮及一氧化氮合酶(nitricoxidesynthase,NOS)的影响,以减轻和预防缺氧对机体的损伤。方法:对进驻海拔3700m高原半年的30名健康青年随机分为银杏叶片组、红景天组和酪氨酸组,每组10人。在未服药时、服药后第15天分别采用功率自行车进行渐增负荷运动至力竭,测定血清中一氧化氮、NOS含量。结果:各组受试者运动后较安静时一氧化氮犤银杏叶片组(101.4±13.7)μmol/L,(67.4±12.2)μmol/L;红景天组(98.8±13.4)μmol/L,(66.7±13.0)μmol/L;酪氨酸组(95.1±13.5)μmol/L,(66.9±12.5)μmol/L犦及NOS犤银杏叶片组(69.9±10.7)U/mL,(43.2±3.8)U/mL;红景天组(67.6±11.0)U/mL,(43.5±4.63)U/mL;酪氨酸组(65.7±10.2)U/mL,(42.9±3.98)U/mL犦均增高,差异有显著性意义(P<0.05或P<0.01)。服药后较服药前一氧化氮增高,差异有非常显著性意义(P<0.01),NOS增高,差异有显著性意义(P<0.05)。结论:银杏叶片、酪氨酸冲剂和红景天均能增强高原运动时NOS活性,使一氧化氮合成增加,可减轻和预防缺氧会对机体造成多种损伤。     

超声治疗对冠心病患者血中一氧化氮和α颗粒膜蛋白140的影响

目的:探讨冠心病患者超声治疗前后一氧化氮和α颗粒膜蛋白140含量测定及临床意义。方法:选用未使用抗血小板药治疗的冠心病患者进行超声治疗,用采用硝酸还原酶法和ELISA双抗体夹心法测定治疗前后一氧化氮和α颗粒膜蛋白140含量。结果:冠心病患者超声治疗前血清一氧化氮水平犤(40.9±12.7)μmol/L犦较对照组犤(21.4±5.3)μmol/L犦显著性升高(P<0.01),治疗后血清一氧化氮水平犤(19.5±9.2)μmol/L犦接近正常对照组;冠心病患者超声治疗前血浆α颗粒膜蛋白140含量犤(29.34±5.36)μg/L犦明显高于正常对照组犤(12.08±4.85)μg/L犦(P<0.01),治疗后有所下降犤(25.53±6.51)μg/L犦,但无显著性意义。且患者超声治疗前后血清一氧化氮和血浆α颗粒膜蛋白140呈显著正相关。结论:冠心病患者体内存在血小板活化,一氧化氮和血小板活化可能共同参与了冠心病发展过程,超声治疗冠心病可能的机制是通过一氧化氮和α颗粒膜蛋白140多种因素共同作用的结果。     

一氧化氮及一氧化氮合酶在哮喘大鼠气道高反应中的作用

目的:探讨一氧化氮及一氧化氮合酶(nitricoxidesynthase,NOS)在哮喘大鼠气道炎症中的作用及激素对其活性的影响,以期为该病的预防、康复措施介入提供理论依据。方法:实验选用雄性豚鼠30只,按随机数字法将豚鼠分为3组:①哮喘组:用100g/L卵蛋白腹腔注射1mL致敏,2周后用10g/L卵蛋白超声雾化吸入致其哮喘发作。②激素组:诱喘同前,每次诱喘前腹腔内注射甲基强的松龙10mg/kg。③对照组:用生理盐水代替诱喘剂。每组分别测定其血浆和肺组织NO2-/NO3-水平、肺组织诱导型NOS(induciblenitricoxidesynthase,iNOS)和原生型NOS(constitutenitricoxidesynthase,cNOS)活性水平,并用组织化学染色法观察NOS在豚鼠哮喘模型肺组织中的分布。结果:3组豚鼠血浆NO2-/NO3-水平差异无显著性意义(P>0.05),哮喘组肺组织中NO2-/NO3-和iNOS活性水平犤(0.87±0.08)μmol/g,(56±14)nmol/g犦明显高于对照组和激素组犤(0.19±0.06)μmol/g,(12±6)nmol/g;(0.18±0.07)μmol/g,(12±5)nmol/g犦(P<0.01)。对照组肺组织化学方法显示的阳性产物呈蓝色沉淀,主要分布于各级支气管上皮细胞,哮喘组及激素组阳性产物变化不明显。哮喘组肺组织i-NOS活性水平和肺组织NO2-/NO3-水平呈高度正相关(r=0.782,P<0.05)。结论:一氧化氮可引起气道高反应性而     

前脑缺血再灌注海马CA1区神经元死亡与一氧化氮的关系

目的:深入研究一氧化氮在迟发性神经元死亡的发生中的作用。方法:四血管闭塞复制大鼠前脑缺血/再灌注模型,观察不同类型一氧化氮合酶(nitric-oxidesynthase,NOS)抑制剂治疗组及对照组海马CA1区一氧化氮浓度及CA1区锥体细胞密度的变化。结果:缺血/再灌注后6h海马CA1区一氧化氮浓度犤(3.83±0.90)μmol/L犦即开始升高犤缺血前为(0.93±0.08)μmol/L犦,至3d达到高峰犤(8.99±0.90)μmol/L〗;左旋硝基精氨酸甲脂(L-NAME)能降低各时相点的一氧化氮水平,氨基胍能降低再灌注后6～24h的一氧化氮水平;但两种NOS抑制剂均不能防止再灌注后3d发生的迟发性神经元死亡,其中L-NAME加重了神经元的损害,而氨基胍可明显地减轻神经元损害,有神经保护作用。结论:前脑缺血海马CA1区的迟发性神经元死亡与缺血/再灌注后的一氧化氮水平增高有关,特别是选择性诱导性NOS的作用可能更为重要。     

蜂胶对慢性阻塞性肺疾病患者肺泡巨噬细胞胞浆游离钙浓度及其生成细胞因子的影响

目的:观察蜂胶对慢性阻塞性肺疾病患者(chronicobstructivepulmonarydisease,COPD)肺泡肺泡巨噬细胞(alveolarmacrophage,AM)游离钙浓度及其生成的白细胞介素8(IL-8)、一氧化氮的影响。方法:采用支气管肺泡灌洗、细胞培养和荧光指示剂方法,测定AM内钙浓度其生成的IL-8和NO。结果:COPD组患者AM内钙浓度犤(68.26±7.24)nmol/L犦,IL-8犤(29.11±9.78)ng/L犦,一氧化氮犤(27.61±8.64)μg/L犦均高于对照组犤(60.61±6.26)nmol/L,(15.42±6.78)ng/L,(13.99±7.40)μg/L犦(t=11.38～36.42,P<0.01)。脂多糖刺激以后,胞内游离钙浓度、IL-8和一氧化氮均较刺激前增高(t=12.65～32.58,P<0.01)。先加蜂胶孵育AM再加入脂多糖,胞浆内游离钙浓度、IL-8和一氧化氮较仅加脂多糖时减少(t=14.72～25.02,P<0.01)。结论:蜂胶可抑制脂多糖引起的犤Ca2+犦i增加,对脂多糖刺激的IL-8和一氧化氮升高也有抑制作用;可调节AM激活,抑制IL-8、一氧化氮分泌。     

一氧化氮对大鼠局灶性脑缺血再灌注所致神经细胞损伤的影响

目的:观察应用硝普钠和一氧化氮合酶(NOS)抑制剂L-NAME对大鼠局灶性脑缺血再灌注所致神经细胞损伤的影响。方法:取SD大鼠44只,按随机数字表法分为4组:假手术组,脑缺血再灌注组,脑缺血再灌注加侧脑室微量注射L-NAME组,脑缺血再灌注加侧脑室微量注射硝普钠组。用栓线法复制大鼠大脑中动脉脑缺血再灌注模型,自颈内、外动脉分叉处起始,假手术组的尼龙栓子插入13mm,其余3组插入(18.0±0.5)mm造成大脑中动脉完全缺血30min,缓慢拔出尼龙栓子形成再灌注状态,L-NAME组和硝普钠组侧脑室微量注射L-NAME和硝普钠进行干预,假手术组和脑缺血再灌注组侧脑室注射等量生理盐水。于再灌注术后12,24h,2,4d分别处死动物取材,紫外分光光度计检测各脑组织一氧化氮含量,免疫组化法测脑组织NOS活性,TUNEL法检测调亡细胞。结果:脑缺血再灌注急性期(术后12h),脑组织一氧化氮含量迅速增高犤(10.14±1.97)mol/g犦,L-NAME明显降低脑组织一氧化氮的含量犤(3.86±1.35)mol/g犦,硝普钠能明显增加脑组织一氧化氮的含量犤(12.46±1.57)mol/g犦,SPSS10.0统计分析软件LSD法统计结果,各组间比较,F=24.07,P<0.05,有明显显著性意义。术后12hL-NAME抑制NOS的活性犤(16.0±1.2)个/视野犦,硝普钠组NOS的表达增强犤(62.0±4.2)个/视野犦,组间比较,F=     

参麻益智胶囊对痴呆大鼠一氧化氮和一氧化氮合酶的影响

目的:证实参麻益胶囊治疗血管性痴呆的药效以及探讨其作用机制。方法:采用颈内动脉注射同种大鼠微血栓悬液制作大鼠血管痴呆(多发性脑梗死)动物模型,设立参麻益智胶囊高、中、低剂量组和阳性药、模型及正常对照组,连续给药6周后,测定血浆、脑组织的一氧化氮含量及一氧化氮合酶(NOS)活性。结果:①模型对照组大鼠血浆中的一氧化氮含量(71.6±24.3)μmol/L和NOS活性(135.9±35.8)nmol/(L·s)明显高于正常对照组(45.5±17.0)μmol/L和(59.3±32.2)nmol/(L·s),P<0.01。②模型对照组大鼠脑组织中的一氧化氮含量(261.0±30.0)μmol/g和NOS活性(66.8±7.2)nmol/(g·s)明显高于正常对照组(191±39)μmol/g和(52.2±2.8)nmol/(g·s),P<0.05。③参麻益智胶囊高、中、低剂量组大鼠血浆中的一氧化氮含量分别为(52.6±15.3),(56.0±17.9),(56.3±12.3)μmol/L和NOS活性(71.9±31.2),(99.7±26.5),(93.0±35.7)nmol/(L·s)明显低于模型对照组(P<0.01)。④参麻益智胶囊高、中、低剂量组大鼠脑组织中的一氧化氮含量和NOS活性明显低于模型对照组(P<0.01)。结论:参麻益智胶囊可降低血管性痴呆大鼠血浆、脑组织中一氧化氮含量及NOS活性。     

Exhaled nitric oxide

We introduce the standard method of measurement of nitric oxide recommended by American thoracic society in 1999 and report the results of exhaled NO and nasal NO in patients with obstructive sleep apnea syndrome(OSAS). Our data showed lower exhaled NO output in the patients with OSAS than that of normal volunteers(NV) and that of patients with simple obesity(SO). On the other hand, nasal NO in the OSAS patients is higher than that of NV and that of SO patients. Also, there were significant relationships between apnea index and exhaled NO and between desaturation during sleep and nasal NO. These findings suggested that NO from lower and upper airway will be a non-invasive maker of sleep disordered breathing in future.     

Modulation of nitric oxide synthase by nitric oxide donor compounds in migraine

A controlled study was performed to assess the involvement of the nitric oxide pathway in migraine pathophysiology. Thirteen patients with migraine without aura and seven clinically healthy subjects (C) were selected. All of the migraine patients were studied both before, during an asymptomatic phase (t ₀), and 1 h after the administration of 5 mg isosorbide dinitrate, a nitric oxide donor able to induce an experimental migraine attack (t ₁). The nitric oxide levels were analyzed as nitrite accumulation in serum samples, in peripheral blood mononuclear cell extracts, and culture supernatants. Basal nitrite levels in serum samples and peripheral blood mononuclear cell culture supernatants of migraine patients and healthy subjects indicated that migraine patients possess an activated nitric oxide synthesis pathway (t ₀ vs. C F=8.16,P<0.01 and F=16.2,P<0.01, respectively). As expected, in the migraine patients treated with the nitric oxide donor, a marked increase of nitrite levels was observed in sera (t ₁ vs.t ₀ P<0.05,t=3.05). In contrast, during the nitric oxide donor-induced migraine attacks a statistically significant decrease of nitrite levels in peripheral blood mononuclear cell culture supernatants was observed (t ₁ vs.t ₀ P<0.01,t=−4.03), whereas a significant increase of nitrite in total cell extracts was detected (t ₁ vs.t ₀ P<0.001,t=−6.89). These preliminary data suggest that nitric oxide could be involved in the neurovascular modifications leading to a migraine attack.     

Exogenous nitric oxide regulates activity and synthesis of vascular endothelial nitric oxide synthase

Background Nitric oxide (NO) – a major signalling molecule of the vascular system – is constitutively produced in endothelial cells (EC) by the endothelial NO synthase (eNOS). Since a reduced NO synthesis is an early sign of endothelial dysfunction and NO delivering drugs are used to substitute the impaired endothelial NO production, we addressed the effect of exogenous NO on eNOS in human umbilical venous endothelial cell cultures. Materials and methods The synthetic NO donor DETA/NO (trade name, but in the following we refer to detNO), that releases NO in a strictly first order reaction with a half life of 20 h, was used in our experiments. Results Short‐term (20–30 min) detNO treatment of EC increases the Ser¹¹⁷⁷ phosphorylation of the constitutively expressed endothelial NOS and the production of endogenous NO generated by eNOS from [³H]arginine. The phosphorylation of eNOS is Akt‐dependent and completely reverted by the phosphatidylinositol‐3 kinase (PI‐3K) inhibitor LY294002. A prolonged continuous exposure of EC to detNO 150 µmol L^?1 over a period of 24–48 h causes a reversible cell cycle arrest at G₁‐phase associated with a larger cell volume and increased cell protein content (hypertrophic phenotype of EC). The eNOS protein and mRNA of the hypertrophic cells and the generation of endogenous NO are reduced but eNOS phosphorylation could still be elevated by stimulation with vascular endothelial growth factor. Conclusions Our data explain clinical studies describing a short‐term but not a long‐term benefit of NO treatment for patients with cardiovascular risk factors. The results could be a rational approach to develop a generation of NO donors accomplishing a retarded release from NO donors that mimic the low continuous pulsatile stress‐induced release of endogenous NO.     

Inhaled nitric oxide down-regulates intrapulmonary nitric oxide production in lipopolysaccharide-induced acute lung injury

OBJECTIVE: To examine whether inhaled nitric oxide (NO) affected the intrapulmonary production of NO, reactive oxygen species, and nuclear factor-kappaB in a lipopolysaccharide (LPS)-induced model of acute lung injury. DESIGN: Prospective, randomized, laboratory study. SETTING: Experimental laboratory at a biomedical institute. SUBJECTS: Twenty male rabbits weighing 2.5-3.5 kg. INTERVENTIONS: Saline or LPS (5 mg/kg of body weight) was administered intravenously with or without NO inhalation (10 ppm) in each group of five rabbits. MEASUREMENTS AND MAIN RESULTS: LPS increased the lung leak index, the neutrophils and NO levels in bronchoalveolar lavage fluid, and NO levels produced by resting and stimulated alveolar macrophages. Inhaled NO decreased the lung leak index, the neutrophils and NO levels as measured by nitrite levels in the lavage fluid, and NO produced by the resting and stimulated alveolar macrophages. Inhaled NO also blocked the activities of reactive oxygen species and nuclear factor-kappaB binding to DNA in lavage cells and in alveolar macrophages. CONCLUSION: Inhaled NO attenuates LPS-induced acute lung injury, possibly by decreasing NO production in the lungs. The mechanism of reducing NO production resulting from inhaled NO may involve, in part, the activities of reactive oxygen species and/or nuclear factor-kappaB.     

大鼠小肠移植术后血清一氧化氮及小肠组织一氧化氮合酶和诱导型一氧化氮合酶活性的变化

目的:研究同种大鼠小肠移植后内源性一氧化氮、一氧化氮合酶(nitricoxidesynthase,NOS)及诱导型一氧化氮合酶(induciblenitricoxidesyn-thase,iNOS)的变化及一氧化氮与急性排斥反应的关系。方法:以大鼠小肠移植为研究对象,16只SD大鼠进行同系移植作为对照组,8只SD大鼠和8只Wistar大鼠进行同种移植作为实验组,两组移植后分别于第3,5,7天同时取血液及小肠组织,病理为常规苏木精-伊红染色观察,血清一氧化氮采用硝酸还原酶法测定,NOS和iNOS采用分光光度法测定。结果:在急性排斥反应发生的早期实验组血清一氧化氮水平与对照组比较显著升高(术后第3,5,7天t值分别为9.7900,9.0073,6.3159,P<0.01),小肠组织NOS及iNOS活性亦显著高于对照组(NOS术后第3,5,7天t值分别为5.9318,9.1237,3.0457,iNOS术后第3,5,7天t值分别为3.2008,5.4930,4.8170,P<0.01)。结论:大鼠小肠移植后NOS及iNOS变化与排斥反应相关,血清一氧化氮水平的检测可作为干预移植措施始动的指标之一。     

The role of nitric oxide synthase/nitric oxide in vascular smooth muscle control

Vascular compliance is dependent on endogenous and exogenous sources of nitric oxide (NO). In a discussion of therapeutics and NO derived via nitric oxide synthase (NOS) enzymes, it is necessary to examine the pathways of each drug to provide the clinical perfusionist with a greater understanding of the role of NOS/NO in vascular function. Endothelial-derived NO is a contributor in the vasoregulation of vascular smooth muscle. Therapeutics seek to mimic the vasodilatory effects of the endogenous NO. The therapeutics included in this review are nitroglycerin, nitroprusside, amyl nitrite, and inhalation of NO. L-Arginine supplementation provides additional substrate for the endogenous pathway that can augment NO production. NO is a small bioactive molecule involved in various biochemical pathways. Dysregulation of NO production can impair normal physiologic control of vascular compliance. Therefore, the purpose of this review is to provide the perfusionist with an understanding of the biochemical and pharmacological aspects of NOS/NO associated with vascular function.     

大鼠创伤性脑水肿一氧化氮及其合成酶的变化

目的：探讨脑损伤后一氧化氮（ＮＯ）及一氧化氮合酶（ＮＯＳ）与脑水肿的关系。方法：建立大鼠创伤性脑水肿模型,按不同时间点处死动物,测定其脑含水量及静脉血ＮＯ 和脑组织中ＮＯＳ。结果：脑创伤后脑含水量随静脉血ＮＯ的增加而增加,组织ＮＯＳ则随ＮＯ 的增加而下降。结论：创伤性脑水肿与血ＮＯ 有密切相关性,组织中ＮＯＳ则是该过程的可能催化剂     

Exhaled nitric oxide as a marker for serum nitric oxide concentration in acute endotoxemia

The main aim of this study was to assess the correlation between exhaled nitric oxide (NO) and serum NO concentrations during the course of endotoxemia. We also assessed whether or not the inducible isoform of NO synthase is responsible for the increase in NO production in endotoxemia animals.

Anesthetized and mechanically ventilated dogs were injected with either saline (control) or Escherichia coli endotoxin (LPS [Lipopolysaccharides]), and the animals were sacrificed 150 minutes later. We measured hemodynamics, exhaled NO, and serum arterial and mixed venous NO concentrations. Western blotting was performed on lung, pulmonary artery, aorta, and kidney tissue samples using anti-inducible NO synthase antibody.

Arterial pressure, cardiac output, and pulmonary arterial pressure in the control group remained unchanged, whereas a significant decline in these parameters was observed in the LPS group. Exhaled NO and serum arterial NO concentrations rose significantly within 30 minutes of endotoxin injection and remained higher than baseline values, whereas mixed venous serum NO did not change from baseline values. There was a significant linear relationship between exhaled NO and arterial serum NO concentrations. By comparison, exhaled NO, and arterial and mixed venous serum NO levels remained unchanged in the control group. Western blotting showed no expression of inducible NO synthase (iNOS) isoform in the control or LPS groups.

These results suggest that exhaled NO accurately reflects changes in arterial serum NO concentration and that the source of enhanced NO release in acute endotoxemia is not the iNOS isoform.