Effect of nitric oxide on toll-like receptor 2 and 4 gene expression in rats with acute lung injury complicated by acute hemorrhage necrotizing pancreatitis

BACKGROUND: Toll-like receptor (TLR) 2/4 might play important roles in mediating proinflammatory cytokine synthesis and release. And nitric oxide (NO) has been used to treat acute respiratory distress syndrome (ARDS). This study aimed to investigate the changes in TLR2/4 gene expression in the lungs of rats with acute lung injury (ALI) complicated by acute hemorrhage necrotizing pancreatitis (AHNP) and the effect of NO on the TLR2/4 gene expression. METHODS: One hundred and ten SD male rats were randomly divided into sham-operated group ( n = 10) , AHNP group (n = 30) , chloroquine-treated group ( n = 30) , and L-Arg-treated group (n =40). The lungs were dissected for lung histological scoring, and bronchoalveolar lavages were harvested for lung injury indexing. TLR2/4 mRNA expression in the lungs was measured by RT-PCR. RESULTS: TLR2/4mRNA was detected in the lungs with low values in the sham-operated group (0.016±0. 210E-2, 0.112 ±0.750E-2) , but it was markedly increased at 3 hours in the AHNP group (0.787±0.751E-2, 1.512 ±1.794E-2) , peaking at 12 hours (1.113 ±6.141E-2, 2.957±2.620E-2; P <0.05 or P <0.01). When lung injuries were aggravated, TNF-α concentrations in the lungs were increased, but NO concentrations were decreased ( P < 0.05 or P < 0.01 ) . When TLR2/4mRNA was inhibited by CQ (3h: 0.313 ± 5.491E-2, 0.005 ±1.419E-3 ; 6h: 0.488 ±7.442E-2, 0.010 ± 1.518E-3; 12h: 0.883 ± 8.911E-2, 0.024 ± 2.760E-3; P< 0.05 or P <0.01) , lung injuries were relieved. NO concentrations in the lungs were increased but TNF-α concentrations were decreased (P <0. 05 or P <0.01). When the rats with AHNP were treated with L-Arg, TLR2/4mRNA expression in the lungs could be effectively inhibited (50mg-T: 0.656 ±3. 977E-2, 1. 501 ±6.111E-2; 100mg-T: 0.260± 0.891E-2, 0.732 ±5.135E-2; 200mg-T: 0.126 ±0.914E-2, 0.414 ± 1.678E-2; 400mg-T: 0.091 ±0.399E-2, 0.287 ± 0.176E-2; P <0.05 or P <0. 01) and lung injuries were relieved. At the same time, NO concentrations in the lungs were markedly increased, but TNF-α concentrations were decreased (P <0.05 or P <0.01). CONCLUSIONS: The expression of TLR2/4mRNA is increased in the lungs in rats with AHNP and lung injuries are aggravated. TLR2/4mRNA gene expression of the lungs of rats with AHNP could be markedly inhibited by NO, leading to the relief of lung injuries.

Effects of glucocorticoid dexamethasone on serum nitric oxide synthase activity and nitric oxide levels in a rat model of lung disease-induced brain injury

In this study, we investigated the effects of dexamethasone, pertussis toxin （a Gi protein inhibitor） and actinomycin （a transcription inhibitor） on serum nitric oxide synthase activity and nitric oxide content in a rat model of lung disease-induced brain injury. High-dose dexamethasone （13 mg/kg） and dexamethasone ＋ actinomycin reduced lung water content, increased serum nitric oxide synthase activity and nitric oxide content, diminished inflammatory cell infiltration in pulmonary alveolar interstitium, attenuated meningeal vascular hyperemia, reduced glial cell infiltration, and decreased cerebral edema. These results demonstrate that high-dose glucocorticoid treatment can reduce the severity of lung disease-induced brain injury by increasing nitric oxide synthase activity and nitric oxide levels.

Ginkgo biloba extract(EGb 761) attenuates lung injury induced by intestinal ischemia/reperfusion in rats:Roles of oxidative stress and nitric oxide

AIM： To investigate the effect of ginkgo biloba extract （EGb 761） on lung injury induced by intestinal ischemia/ reperfusion （ Ⅱ/R）. METHODS： The rat model of Ⅱ/R injury was produced by damping the superior mesenteric artery for 60 min followed by reperfusion for 180 min. The rats were randomly allocated into sham, Ⅱ/R, and EGb ＋Ⅱ/R groups. In EGb ＋Ⅱ/R group, EGb 761 （100 mg/kg per day） was given via a gastric tube for 7 consecutive days prior to surgery. Rats in Ⅱ/R and sham groups were treated with equal volumes of the vehicle of EGb 761. Lung injury was assessed by light microscopy, wet-todry lung weight ratio （W/D） and pulmonary permeability index （PPT）. The levels of malondialdehyde （MDA） and nitrite/nitrate （NO2/NO3）, as well as the activities of superoxide dismutase （SOD） and myeloperoxidase （MPO） were examined. Western blot was used to determine the expression of inducible nitric oxide synthase （iNOS）. RESULTS： EGb 761 markedly improved mean arterial pressure and attenuated lung injury, manifested by the improvement of histological changes and significant decreases of pulmonary W/D and PPT （P 〈 0.05 or 0.01）.Moreover, EGb 761 markedly increased SOD activity, reduced MDA levels and MPO activity, and suppressed NO generation accompanied by down-regulation of iNOS expression （P 〈 0.05 or 0.01）. CONCLUSION： The results indicate that EGb 761 has a protective effect on lung injury induced by Ⅱ /R, which may be related to its antioxidant property and suppressions of neutrophil accumulation and iNOS- induced NO generation. EGb 761 seems to be an effective therapeutic agent for critically ill patients with respiratory failure related to Ⅱ/R.

Acute respiratory distress syndrome and lung injury: Pathogenetic mechanism and therapeutic implication

To review possible mechanisms and therapeutics for acute lung injury(ALI) and acute respiratory distress syndrome(ARDS). ALI/ARDS causes high mortality. The risk factors include head injury, intracranial disorders, sepsis, infections and others. Investigations have indicated the detrimental role of nitric oxide(NO) through the inducible NO synthase(i NOS). The possible therapeutic regimen includes extracorporeal membrane oxygenation, prone position, fluid and hemodynamic management and permissive hypercapnic acidosis etc. Other pharmacological treatments are anti-inflammatory and/or antimicrobial agents, inhalation of NO, glucocorticoids, surfactant therapy and agents facilitating lung water resolution and ion transports. β-adrenergic agonists are able to accelerate lung fluid and ion removal and to stimulate surfactant secretion. In con-scious rats, regular exercise training alleviates the endotoxin-induced ALI. Propofol and N-acetylcysteine exert protective effect on the ALI induced by endotoxin. Insulin possesses anti-inflammatory effect. Pentobarbital is capable of reducing the endotoxin-induced ALI. In addition, nicotinamide or niacinamide abrogates the ALI caused by ischemia/reperfusion or endotoxemia. This review includes historical retrospective of ALI/ARDS, the neurogenic pulmonary edema due to head injury, the detrimental role of NO, the risk factors, and the possible pathogenetic mechanisms as well as therapeutic regimen for ALI/ARDS.

Acute lung injury and acute respiratory distress syndrome： experimental and clinical investigations

Acute lung injury （ALl） or acute respiratory distress syndrome （ARDS） can be associated with various disorders. Recent investigation has involved clinical studies in collaboration with clinical investigators and pathologists on the pathogenetic mechanisms of ALl or ARDS caused by various disorders. This literature review includes a brief historical retrospective of ALI/ARDS, the neurogenic pulmonary edema due to head injury, the long-term experimental studies and clinical investigations from our laboratory, the detrimental role of NO, the risk factors, and the possible pathogenetic mechanisms as well as therapeutic regimen for ALI/ARDS.

Neuroprotection and its molecular mechanism following spinal cord injury

Acute spinal cord injury initiates a complex cascade of molecular events termed ＇secondary injury＇, which leads to progressive degeneration ranging from early neuronal apoptosis at the lesion site to delayed degeneration of intact white matter tracts, and, ultimately, expansion of the initial injury. These secondary injury processes include, but are not limited to, inflammation, free radical-induced cell death glutamate excitotoxicity, phospholipase A2 activation, and induction of extrinsic and intrinsic apoptotic pathways, which are important targets in developing neuroprotective strategies for treatment of spinal cord injury. Recently, a number of studies have shown promising results on neuroprotection and recovery of function in rodent models of spinal cord injury using treatments that target secondary injury processes including inflammation, phospholipase A2 activation, and manipulation of the PTEN-AktJmTOR signaling pathway. The present review outlines our ongoing research on the molecular mechanisms of neuroprotection in experimental spinal cord injury and briefly summarizes our earlier findings on the therapeutic potential of pharmacological treatments in spinal cord injury.

Curcumin protects against ischemic spinal cord injury The pathway effect

Inducible nitric oxide synthase and N-methyI-D-aspartate receptors have been shown to participate in nerve cell injury during spinal cord ischemia. This study observed a protective effect of curcumin on ischemic spinal cord injury. Models of spinal cord ischemia were established by ligating the lumbar artery from the left renal artery to the bifurcation of the abdominal aorta. At 24 hours after model establishment, the rats were intraperitoneally injected with curcumin, Reverse transcrip- tion-polymerase chain reaction and immunohistochemical results demonstrated that after spinal cord ischemia, inducible nitric oxide synthase and N-methyI-D-aspartate receptor mRNA and protein expression significantly increased. However, curcumin significantly decreased inducible nitric oxide synthase and N-methyI-D-aspartate receptor mRNA and protein expression in the ischemic spinal cord. Tadov scale results showed that curcumin significantly improved motor function of the rat hind limb after spinal cord ischemia. The results demonstrate that curcumin exerts a neuroprotective ef- fect against ischemic spinal cord injury by decreasing inducible nitric oxide synthase and N-methyI-D-aspartate receptor expression.

Osteopontin protects against hyperoxia-induced lung injury by inhibiting nitric oxide synthases

Background Exposure of adult mice to more than 95% O_2 produces a lethal injury by 72 hours. Nitric oxide synthase （NOS） is thought to contribute to the pathophysiology of murine hyperoxia-induced acute lung injury （ALI）. Osteopontin （OPN） is a phosphorylated glycoprotein produced principally by macrophages. OPN inhibits inducible nitric oxide synthase （iNOS）, which generates large amounts of nitric oxide production. However, the relationship between nitric oxide and endogenous OPN in lung tissue during hyperoxia-induced ALI has not yet been elucidated, thus we examined the role that OPN plays in the hyperoxia-induced lung injury and its relationships with NOS.Methods One hundred and forty-four osteopontin knock-out （KO） mice and their matched wild type background control （WT） were exposed in sealed cages 〉95% oxygen or room air for 24-72 hours, and the severity of lung injury was assessed; expression of OPN, endothelial nitric oxide synthase （eNOS） and iNOS mRNA in lung tissues at 24,48 and 72 hours of hyperoxia were studied by reverse transcription-polymerase chain reaction （RT-PCR）; immunohistochemistry （IHC） was performed for the detection of iNOS, eNOS, and OPN protein in lung tissues.Results OPN KO mice developed more severe acute lung injury at 72 hours of hyperoxia. The wet/dry weight ratio increased to 6.85±0.66 in the KO mice at 72 hours of hyperoxia as compared to 5.31±0.92 in the WT group （P〈0.05）. iNOS mRNA （48 hours： 1.04±0.08 vs. 0.63±0.09, P〈0.01; 72 hours： 0.89±0.08 vs. 0.72±0.09, P〈0.05） and eNOS mRNA （48 hours： 0.62±0.08 vs. 0.43±0.09, P〈0.05; 72 hours： 0.67±0.08 vs. 0.45±0.09, P〈0.05） expression was more significantly increased in OPN KO mice than their matched WT mice when exposed to hyperoxia. IHC study showed higher expression of iNOS （20.54±3.18 vs. 12.52±2.46, P 〈0.05） and eNOS （19.83±5.64 vs. 9.45±3.82, P 〈0.05） in lung tissues of OPN KO mice at 72 hours of hyperoxia. Conclusion OPN can protect against hyperoxia-induced lung injury by inhibiting NOS.

毛蕊花糖苷调节IRE1α/TXNIP/NLRP3信号通路对重症急性胰腺炎模型大鼠肺损伤的影响

目的探讨毛蕊花糖苷(acteoside,ACT)调节肌醇需求酶1α(inositol-requiring enzyme 1α,IRE1α)/硫氧还蛋白相互作用蛋白(thioredoxin interacting protein,TXNIP)/核苷酸结合寡聚化结构域样受体蛋白3(nucleotide binding oligomerization domain-like receptor protein 3,NLRP3)通路对重症急性胰腺炎(severe acute pancreatitis,SAP)模型大鼠肺损伤的影响。方法大鼠随机分为SAP组、正常组、毛蕊花糖苷低剂量(ACT-L)组和高剂量(ACT-H)组、乌司他丁组、ACT-H+空载体组、ACT-H+IRE1α过表达腺病毒载体(Ad-IRE1α)组,每组12只。除正常组外,其他组大鼠均通过向胆胰管注入5%牛磺胆酸钠溶液的方式构建SAP模型,建模成功后给药2天,一天一次。检测血清脂肪酶、淀粉酶水平及肺湿重/干重比值的变化;HE染色检测胰腺、肺组织病理变化并评估病理评分;试剂盒检测肺组织中活性氧(reactive oxygen species,ROS)、丙二醛(malondialdehyde,MDA)、超氧化物歧化酶(superoxide dismutase,SOD)水平;ELISA检测肺组织中白细胞介素(IL)-18、IL-1β水平;蛋白质印迹检测肺组织中IRE1α、TXNIP、NLRP3、半胱氨酸蛋白酶-1(caspase-1)蛋白水平。结果与正常组相比,SAP组大鼠胰腺水肿,有大量细胞坏死以及炎症细胞浸润,肺组织炎症细胞浸润明显,肺泡充血、肺泡壁水肿严重,胰腺、肺组织病理评分、血清中脂肪酶、淀粉酶水平、肺湿重/干重比值、肺组织中MDA、ROS水平、IL-18、IL-1β水平及IRE1α、TXNIP、NLRP3、caspase-1蛋白升高,肺组织中SOD水平降低(P<0.05);与SAP组相比,ACT-L组、ACT-H组、乌司他丁组大鼠胰腺及肺组织损伤有所改善,胰腺、肺组织病理评分、血清中脂肪酶、淀粉酶水平、肺湿重/干重比值、肺组织中MDA、ROS水平、IL-18、IL-1β水平及IRE1α、TXNIP、NLRP3、caspase-1蛋白降低,肺组织中SOD水平升高(P<0.05);与ACT-H+空载体组相比,ACT-H+Ad-IRE1α组大鼠胰腺及肺组织损伤加剧,胰腺、肺组织病理评分、血清中脂肪酶、淀粉酶水平、肺湿重/干重比值、肺组织中MDA、ROS水平、IL-18、IL-1β水平及IRE1α、TXNIP、NLRP3、caspase-1蛋白升高,肺组织中SOD水平降低(P<0.05)。结论ACT改善SAP大鼠肺损伤的机制可能与抑制IRE1α/TXNIP/NLRP3通路活化有关。

内源性一氧化氮在内毒素引起的肺动脉高压和肺损伤中的作用

本实验观察了家兔静脉内注入内毒素的主要成分脂多糖（ＬＰＳ）后平均动脉血压（ＭＡＰ）、肺动脉压（ＰＡＰ）及入、出肺血ＮＯ含量的变化，并观察了静脉内预注入ＮＯ生成抑制剂Ｎω硝基Ｌ精氨酸（ＬＮＮＡ）及诱生型ＮＯ生成抑制剂氨基胍（ＡＧ）后ＰＡＰ和肺损伤的变化。结果观察到：家兔ＬＰＳ注入后，ＭＡＰ均明显下降，ＬＰＳ注入后０５、１、１５、２ｈＰＡＰ明显增高（Ｐ＜００５）。ＬＰＳ注入后ＰＡＰ的高峰期（１ｈ）入肺血ＮＯ含量明显降低，出肺血ＮＯ无明显变化。与对照组相比，ＬＰＳ注入后３ｈ出肺血ＮＯ含量和５ｈ入、出肺血ＮＯ含量均明显增多。相关分析表明，兔ＬＰＳ注入前和ＬＰＳ注入后１ｈＰＡＰ与入肺血ＮＯ含量呈明显的负相关，而ＬＰＳ注入后３ｈ和５ｈ两者相关不明显。静脉预注入ＬＮＮＡ后，ＬＰＳ处理组的动物ＰＡＰ明显增高，入、出肺血丙二醛（ＭＤＡ）含量也明显增高，动物生存率明显降低。肺组织光镜下可见肺萎陷和小血管淤血加重，白细胞明显增加。静脉预注入ＡＧ后，ＬＰＳ处理组的动物ＭＡＰ在３～５ｈ明显增高，此时ＰＡＰ无明显改变，但５ｈ时血中ＭＤＡ含量明显减低，５ｈ时与ＬＰＳ组相比肺萎陷和小血管淤血减轻，白细胞也明显减少。以上结果?

吸入一氧化氮对急性肺损伤小鼠肺组织炎症反应的影响

目的 :探讨吸入一氧化氮 (NO)对内毒素〔即脂多糖 (L PS)〕诱导的急性肺损伤小鼠肺组织炎症反应的影响。方法 :利用腹腔内注射 L PS诱导小鼠急性肺损伤模型 ,按随机数字表法将动物分为 L PS组和 L PS+吸入 NO2 0× 10 - 6组。 L PS注射前 (0时 ,即正常对照 )及注射后 1、3、6和 12小时处死小鼠 (n=6 ) ,分别测定肺组织湿重 /干重 (W/D)比值 ,同时用迁移率改变电泳法 (EMSA)检测核因子κB(NFκB)的活性 ,用酶联免疫吸附法 (EL ISA )检测肿瘤坏死因子α(TNFα)和白介素 10 (IL 10 )的浓度 ,用逆转录聚合酶链反应(RT PCR)法检测 TNFα m RNA及 IL 10 m RNA的表达 ,并观察肺组织病理改变。结果 :L PS注射后 3、6、12小时 ,W/D分别为 4 .80± 0 .31、4 .82± 0 .10和 4 .6 3± 0 .18,明显高于正常对照 (3.6 7± 1.0 4 ,P均 <0 .0 5 )。吸入 2 0× 10 - 6 NO后 3和 12小时 ,W/D分别为 4 .0 4± 0 .77和 4 .2 4± 0 .75 ,显著低于 L PS组 (P均 <0 .0 5 )。吸入 NO2 0× 10 - 6 6小时后 ,小鼠肺组织核蛋白 NFκB活性为 2 5 0 .6± 5 1.5 ,明显低于 L PS组 (40 5 .7± 6 2 .4 ,P<0 .0 5 )。与 L PS组比较 ,吸入 NO后 3～ 12小时 ,肺组织匀浆中 TNFα和 IL 10浓度均明显降低。吸入 NO后 6小时 ,肺组织匀浆中

大鼠急性肺损伤时iNOS mRNA和eNOS mRNA表达的时相变化

目的 :观察内毒素性急性肺损伤时肺组织中一氧化氮 (NO)和一氧化氮合酶mRNA的时相变化 ,并探讨其相互关系。方法 :用内毒素 (LPS)复制急性肺损伤模型 ,分别测定 0 .5 ,1,2 ,3,4h各组肺组织NO和丙二醛 (MDA)的含量 ;用原位杂交方法检测各组大鼠肺组织中诱导型一氧化氮合酶mRNA(iNOSmRNA)和内皮型一氧化氮合酶mRNA(eNOSmRNA)的表达水平。结果 :大鼠给予LPS后 ,①肺组织MDA含量随时间延长而逐渐增加 ,不同时点的均值互有差异 (P <0 .0 5 ) ,并且均显著高于正常对照组 (P <0 .0 5 ) ;②各时点肺组织NO含量和iNOSmRNA表达量均显著大于正常对照组 (P <0 .0 5 ) ,并且均在 2h时达到高峰 ,以后呈下降趋势。二者的变化呈显著正相关 (P <0 .0 1) ;③ 2h前 (含 2h)肺组织MDA含量随iNOSmRNA表达增加所致的NO产量增多而增加 ,2h后二者变化趋势相反 ;④各时点肺组织eNOSmRNA表达量与正常对照组比差异均无显著性。结论 :内毒素性急性肺损伤时 ,肺组织iNOSmRNA大量表达 ,导致内源性NO爆发式产生 ,从而介导肺损伤。NO产量在静注内毒素后 2h达到高峰 ,以后呈下降趋势。

一氧化氮和过氧亚硝基阴离子在肢体缺血再灌注致肺损伤中的作用

目的 :观察肢体缺血再灌注致肺损伤时肺组织中一氧化氮 (NO)及过氧亚硝基阴离子 (ONOO-)的变化 ,以探讨二者在此种损伤中的作用。方法 :采用夹闭大鼠腹主动脉下段造成双下肢缺血和再灌注后肺损伤模型 ,分别测定假手术组、缺血 4h组、缺血 4h再灌注 1h组及再灌注 4h组肺组织匀浆中超氧化物歧化酶 (SOD)活性和丙二醛 (MDA)、NO-2 /NO-3含量变化 ;应用免疫组化方法测定上述各组肺组织中诱导型一氧化氮合酶 (iNOS)及ONOO-体内生成标志物硝基酪氨酸 (NT)的变化。结果 :肢体缺血再灌注后 1h和 4h肺组织中MDA和NO-2 /NO-3的含量显著高于对照组和单纯缺血组 (P <0 .0 5 ) ,而SOD活性则显著低于此两组 (P <0 .0 5 ) ,并出现大量iNOS及NT阳性信号。结论 :肢体缺血再灌注致肺损伤时肺组织中有大量NO和ONOO-产生 ,脂质过氧化增强 ,提示ONOO-参与介导此种肺损伤。

肠系膜淋巴管结扎对失血性休克大鼠肺组织一氧化氮及其表达的影响

目的 观察结扎肠系膜淋巴管对不同时期重症失血性休克大鼠肺组织一氧化氮（NO）及其表达的影响，探讨肠淋巴途径在休克大鼠急性肺损伤（ALI）中的作用。方法 雄性Wistar大鼠78只，按随机数字表法分为假手术组（n=6）、休克组（n=42）和结扎组（n=30）。休克组与结扎组复制重症失血性休克模型，结扎组于休克复苏后行肠系膜淋巴管结扎术；休克组于休克后90min、输液复苏后0h，休克组及结扎组于输液复苏后1、3、6、12和24h各时间点处死大鼠，制备肺组织匀浆，检测NO及其合酶的变化；用逆转录-聚合酶链反应（RT—PCR）测定各组大鼠肺组织诱生型一氧化氮合酶（iNOS）．mRNA表达。结果 休克组大鼠复苏后3h肺组织NO含量、NOS活性及iNOSmRNA表达开始升高，复苏后6～12h持续在较高水平，均显著高于假手术组、休克后90min及复苏后0h（P〈0．05或P〈0．01）；结扎组仅于3h和6h增高，且结扎组复苏后6、12和24h肺组织NO含量、NOS活性以及iNOSmRNA表达均显著低于休克组相同时间点（P〈0．05或P〈0．01）。结论 肠系膜淋巴管结扎可降低重症失血性休克大鼠肺组织NO生成及iNOSmRNA表达，从而减轻肺损伤。

慢性阻塞性肺病患者氧化应激状态及其与糖皮质激素受体水平的相关性

目的观察不同时期慢性阻塞性肺疾病(COPD)患者全身及气道局部氧化应激水平的变化及其与糖皮质激素受体的相关性。方法检测33例COPD急性加重期患者(A组)、27例COPD稳定期患者(B组)、14例健康吸烟者(C组)、14例健康不吸烟者(D组)诱导痰及血浆中MDA、GSH水平和SOD、GSH-PX活性,及外周血有核细胞糖皮质激素受体(GR)水平、血皮质醇、ACTH水平。结果A、B、C、D组诱导痰和血浆MDA含量呈下降趋势,GSH、SOD、GSH-PX水平呈上升趋势,各组间差别有统计学意义(P<0.05);C组血浆和诱导痰的SOD水平低于D组(P<0.05),其他指标C、D组间差异统计学无意义(P>0.05)。A、B、C、D4组间血皮质醇及ACTH水平差别无意义(P>0.05),而GR水平依次呈上升趋势,分别为(1565±719)、(2069±488)、(2739±926)、(4793±1415)结合单位,各组间差别有统计学意义(P<0.05)。控制吸烟指数后,COPD患者外周血有核细胞GR水平与血浆及诱导痰SOD的相关系数分别为0.512、0.564,P<0.001,有统计学意义。结论COPD患者全身和气道局部均存在氧化/抗氧化失衡,尤以急性加重期患者更为明显;SOD活力下降可能是COPD患者糖皮质激素受体水平下降的原因之一。

吸入不同浓度一氧化氮对急性肺损伤小鼠肺组织炎症反应的影响

目的 探讨吸入一氧化氮 (NO)对急性肺损伤 (ALI)小鼠肺组织炎症反应的影响。方法 脂多糖 (LPS)腹腔注射诱导小鼠ALI模型 ,吸入不同浓度NO ,测定肺组织核因子 (NF) κB活性及肿瘤坏死因子 (TNF)α、白介素 (IL) 1 0mRNA的表达。结果 与LPS组 (A组 )比较 ,LPS +吸入NO 5 ppm(B组 )、LPS +吸入NO 2 0 ppm(C组 ) 1 2小时湿重 /干重 (W /D)显著降低 ,LPS +吸入NO4 0ppm(D组 )无明显差异。LPS注射后肺组织NF κB活性明显增强 ,6小时达到峰值 4 0 6± 6 2 ,显著高于LPS注射前 (45± 31 ,P <0 0 5 )。吸入NO 5 ppm和 2 0 ppm 6小时后 ,NF κB活性明显低于LPS组 (P <0 0 5 )。但吸入 4 0ppmNF κB活性在 3小时、6小时明显下降后 ,1 2小时又明显升高。B组和C组肺组织TNF α和IL 1 0浓度及mRNA表达在 3～ 1 2小时均明显降低 ,但D组吸入NO 4 0 ppm1 2小时 ,TNF α表达与LPS组无显著差异。吸入NO后各组IL 1 0表达均降低。结论 吸入 5 ppm和 2 0ppmNO可抑制LPS介导的NF κB活化 ,下调炎症因子表达 ,改善ALI ,但吸入 4 0 ppmNO加重肺损伤。

卡托普利对风湿性心脏病换瓣手术病人肺缺血-再灌损伤的延迟期保护作用

目的 :研究卡托普利对风湿性心脏病换瓣手术病人肺缺血 再灌损伤的延迟期保护作用。方法 :2 0例风湿性心脏病换瓣病人被随机分为卡托普利组与对照组。卡托普利组于术前 96～ 4 8h口服 1mg·kg- 1 ·d- 1 的卡托普利片 ,对照组口服安慰剂。分别于CPB前 ,CPB后 1h ,3h ,6h ,12h测量肺血管阻力 (PVR)及肺泡—动脉血氧梯度差 (A aDO2 ) ,并于CPB前、CPB后 30min检测左、右心房血中性粒细胞 (PMN)及左房血超氧化物歧化酶 丙二醛 (SOD MDA) ,NO ,AngⅡ值。结果 :CPB后各时间点卡托普利组PVR均较对照组为低。CPB后 1h ,3h ,6h卡托普利组A aDO2 值均显著低于对照组。CPB后 30min卡托普利组右房—左房血PMN计数差值、MDA水平明显小于对照组 ,左房血SOD ,NO水平显著高于对照组。两组CPB后 30min左房血AngⅡ水平差异无显著性。结论 :风湿性心脏病换瓣病人术前 96～ 72h口服卡托普利片 (1mg·kg- 1 ·d- 1 )对病人肺组织缺血—再灌注损伤具有延迟期保护作用 。

L-精氨酸和氨基胍对大鼠内毒素性肺损伤治疗作用的实验研究

目的:观察L-精氨酸(L-arginine)和一氧化氮合酶抑制剂氨基胍(AG)对内毒素性肺损伤的治疗作用。方法:采用静脉注射脂多糖(LPS)制备内毒素性肺损伤大鼠模型。将48只SD大鼠随机分为6组:空白对照组、LPS模型组、AG治疗组(50mg/kg)、L-精氨酸(500mg/kg)、(250mg/kg)和L-精氨酸(250mg/kg)+AG(50mg/kg)治疗组。经腹腔给药,实验过程中监测大鼠平均动脉压(MAP),定时取静脉血测定血浆中NO含量,于规定时间处死大鼠,迅速取出肺脏,观察LPS引起大鼠急性肺损伤后肺系数、肺水肿情况和肺组织中丙二醛(MDA)含量、一氧化氮合酶(NOS)、超氧化物歧化酶(SOD)活性的变化,以及L-精氨酸和氨基胍分别单独给药和二者联合给药对内毒素性肺损伤的治疗作用。结果:氨基胍可明显升高MAP,降低肺系数和肺含水量,减少血浆中NO含量,可显著降低肺组织中NOS活性,减少MDA含量,增强SOD活性,改善肺损伤;L-精氨酸可明显降低肺系数和肺含水量,减少MDA含量,增强SOD活性;L-精氨酸与氨基胍联合应用亦得到上述类似结果。结论:L-精氨酸和氨基胍分别单独给药以及二者联合给药对内毒素性肺损伤均具有治疗作用。

核转录因子-κB及一氧化氮在急性肺损伤发生中的作用

目的 探讨核转录因子 κB(NF κB)及诱导型一氧化氮合酶 (iNOS)、一氧化氮 (NO)在大鼠急性肺损伤 (ALI)发生机制中的作用 ,为临床治疗ALI寻找新的治疗措施提供理论依据。方法 应用脂多糖 (LPS)静脉注射复制大鼠ALI模型。将 32只SD大鼠随机分成 4组 :正常对照组 (NS组 )、ALI模型组 (LPS组 )、N 乙酰半胱氨酸 (NAC)干预组及地塞米松 (DXM)干预组 ,后两组分别以NAC(2 0 0mg/kg)和DXM(70mg/kg)预处理。各组大鼠均于注射LPS或生理盐水后 4h处死 ,观察肺病理改变 ,测定肺系数 ,免疫组化方法检测肺NF κB、iNOS染色强度 ,测定血清NO、丙二醛 (MDA)含量。结果 LPS组大鼠肺病理见明显ALI表现 ,肺NF κB、iNOS染色强度和血清NO亦明显高于NS组 (P <0 0 5 ) ,肺系数及血清MDA水平均明显高于NS组 (P <0 0 5 )。NAC干预组及DXM干预组肺NF κB、iNOS染色强度和血清NO均明显低于LPS组 (P <0 0 5 ) ,肺病理表现较LPS组明显好转 ,肺系数及MDA水平均明显低于LPS组 (P <0 0 5 )。结论 大鼠肺部NF κB活化 ,肺iNOS表达增多 ,大量NO生成共同参与了ALI的发生。抑制NF κB的表达 。

吸入一氧化氮对急性肺损伤大鼠肺组织炎症的影响

目的观察吸入不同浓度一氧化氮(NO)对急性肺损伤(ALI)大鼠肺组织的影响。方法将24只SD大鼠随机分为对照组、ALI模型组、低浓度NO组和高浓度NO组,每组6只。ALI模型组、低浓度NO组和高浓度NO组气管内滴注脂多糖(LPS)复制大鼠急性肺损伤模型,对照组气管内滴注生理盐水。接动物呼吸机,对照组与ALI模型组吸入正常空气,低浓度NO组和高浓度NO组吸入的空气中加入20×10-6mg/L和100×10-6mg/L的NO。观察各组大鼠6h后的肺部病理学变化,进行肺部炎症评分。采用免疫组化检测大鼠气道Toll样受体4(TLR4)的表达,ELISA法检测肺组织匀浆IL-6的水平。结果TLR4及IL-6在对照组大鼠气道内有广泛分布和表达。ALI模型组大鼠支气管、肺内炎症程度明显高于对照组,主支气管和肺内细支气管上皮细胞内TLR4表达明显增强,IL-6的含量较正常组明显增加。低浓度NO组气管和主支气管的炎症程度明显减轻,TLR4及IL-6的表达量较ALI模型组组明显减少。但高浓度NO组肺组织炎症程度、TLR4表达与ALI模型组无显著差异,IL-6水平反而显著增高。结论吸入适当浓度NO可降低ALI时肺组织TLR4及IL-6表达的增高,减轻肺组织炎症。