基质金属蛋白酶-2及其抑制物-2在高氧致慢性肺疾病新生大鼠肺组织中的动态变化及意义

目的 探讨基质金属蛋白酶-2(MMP-2)及其抑制物-2(TIMP-2)mRNA和蛋白在高氧致慢性肺疾病(CLD)新生大鼠肺组织中的动态表达规律以及在CLD发生中的作用和意义.方法 足月新生大鼠出生后12 h内分别持续吸入0.90～0.95的高氧或空气,于1、3、7、14和21 d取肺组织进行苏木素-伊红(HE)染色,辐射状肺泡计数(RAC);用免疫组化和逆转录-聚合酶链反应(RT-PCR)方法分别检测肺组织MMP-2和TIMP-2的蛋白及mRNA表达.结果 病理观察高氧组早期炎症反应,7 d出现肺泡发育阻滞,最终纤维化;在7 d时高氧组RAC值较空气组降低(P＜0.05),14 d和21 d的差异更为显著(P均＜0.01);在高氧暴露3 d时,MMP-2的蛋白和mRNA表达均较空气组增强(P＜0.05和P＜0.01),14 d时MMP-2蛋白表达减弱(P＜0.05),而mRNA水平两组间差异无统计学意义;TIMP-2的蛋白和mRNA表达在两组中各时间点比较差异均无统计学意义.结论 高氧暴露后,肺组织中MMP-2/TIMP-2表达失衡,使细胞外基质降解异常,可能是高氧致肺早期炎性损伤和最终肺间质纤维化及发育障碍的机制之一.     

盐酸氨溴索对新生大鼠高氧慢性肺损伤肺纤维化的干预研究

目的探讨盐酸氨溴索对高氧性肺损伤新生大鼠肺组织纤维化的干预作用。方法出生12 h内的清洁级SD大鼠30只作为研究对象,随机分成3组(每组10只):空气对照组(A组)、高氧组(B组)、高氧加盐酸氨溴索组(C组)。除A组外,B组和C组均建立高氧肺损伤动物模型。C组新生大鼠每天腹腔注射溶于9 g/L氯化钠溶液中的盐酸氨溴索[20 mg/(kg.d)],A、B组新生鼠每日腹腔注射等量9 g/L氯化钠溶液,持续14 d。第14 d处死,取其肺组织切片,伊红染色法(HE)观察其肺组织病理变化;Masson三色染色图像定量分析计算其胶原纤维阳性面积百分比,酶联免疫分析法(ELISA法)测定肺组织Ⅲ和Ⅳ型胶原蛋白,判断其肺纤维化程度。结果 B组第14天肺组织病理发现间质细胞增多,肺泡数目减少,肺组织出现纤维化改变;C组肺组织病理改变明显减轻。与A组比较,B组Ⅲ型胶原及Ⅳ型胶原表达明显增多,胶原纤维阳性面积百分比明显增高(P<0.05)。C组与B组比较,Ⅲ型胶原及Ⅳ型胶原表达及胶原纤维阳性面积百分比明显下降(P<0.05)。结论盐酸氨溴索早期干预可减轻高氧性肺损伤新生大鼠的肺组织纤维化程度。     

红霉素在早产鼠高氧肺损伤中对白细胞介素6、8及γ-谷氨酰半胱氨酸合成酶表达的影响

目的 探讨红霉素在早产鼠高氧肺损伤中对白细胞介素6 （IL-6）,IL-8及γ-谷氨酰半胱氨酸合成酶（γ-GCS）的干预作用.方法 96只早产新生SD大鼠生后1d分为四组：Ⅰ组空气暴露＋生理盐水、Ⅱ组空气暴露＋红霉素、Ⅲ组高氧暴露＋生理盐水、Ⅳ组高氧暴露＋红霉素,每组各24只.四组分别于高氧或空气暴露后1、7、14d处死取肺组织做病理学检查.采取双抗体夹心酶联免疫吸附试验分析肺组织匀浆细胞因子IL-6、IL-8和γ-GCS的水平,并采取半定量逆转录聚合酶链反应测定γ-GCS mRNA的表达.结果 Ⅰ、Ⅱ组肺组织无明显病理改变,Ⅲ组肺泡炎性改变及水肿较Ⅳ组更为明显.Ⅳ组γ-GCS水平在7、14 d较Ⅲ组降低,但是γ-GCS mRNA表达较γ-GCS mRNA均明显增强（P均＜0.05）.Ⅲ组1、7、14 d IL-6及IL-8水平较Ⅰ组均显著增强（P均＜0.05）.Ⅳ组IL-6水平在1、7、14d与Ⅲ组比较,差异均有统计学意义（P均＜0.05）,而IL-8水平仅在7、14d较Ⅲ组明显下降（P均＜0.05）.结论 氧化爆发诱导的炎症介质IL-6及IL-8参与高氧肺损伤发病过程,红霉素可抑制其释放,影响γ-GCS活性从而提高谷胱甘肽抗氧化能力.     

饱和氢气盐水对大鼠急性肺损伤的保护作用

目的 探讨饱和氢气盐水在油酸导致的大鼠急性肺损伤(ALI)中的作用及其机制.方法 将健康成年SD大鼠80只随机分为4组:对照(Ⅰ)组、肺损伤(Ⅱ)组、肺损伤静脉H2干预(Ⅲ)组和肺损伤腹腔H2干预(Ⅳ)组,每组20只.检测血气分析;肺组织髓过氧化物酶(MPO)活性、丙二醛(MDA)以及肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)和NF-kB p65含量;并观察肺组织病理变化.结果 与注射油酸前比较,Ⅱ、Ⅲ和Ⅳ组在注射油酸3h后PaO2显著降低(P＜0.05).同时与Ⅰ组比较也存在PaO2显著降低(P＜0.05).此外,Ⅲ和Ⅳ组PaO2显著高于Ⅱ组(P＜0.05),且Ⅳ组PaO2高于Ⅲ组(P＜0.05).与Ⅰ组比较,Ⅱ组肺组织MPO活性及MDA水平显著增加(P＜0.01),Ⅲ和Ⅳ组肺组织MPO活性及MDA水平明显增加(P＜0.05),Ⅲ和Ⅳ组肺组织MPO活性及MDA水平与Ⅰ组比较显著降低(P＜0.05),且Ⅳ组肺组织MPO活性及MDA水平较Ⅲ组低(P＜0.05).Ⅱ、Ⅲ、Ⅳ组大鼠肺组织TNF-α、IL-1β和NF-κB p65水平明显高于Ⅰ组(P＜0.05).与Ⅱ组比较饱和氢气盐水治疗可降低油酸致肺损伤大鼠肺组织TNF-α、IL-1β和NF-κB p65水平(P＜0.05),且腹腔给药治疗较尾静脉给药治疗可更进一步降低油酸致肺损伤大鼠肺组织TNF-α、IL-1β和NF-κB p65水平(P＜0.05).结论 饱和氢气生理盐水能够降低大鼠油酸肺损伤模型中肺的损伤程度,且经腹腔注射给药效果更好,其机制可能与氢分子在体内的选择性抗氧化作用以及对肺组织内炎细胞浸润和炎症级联反应的抑制有关.     

高氧致新生大鼠肺损伤中氧化应激与基质金属蛋白酶的关系

目的探讨氧化应激和基质金属蛋白酶-9（MMP-9）／基质金属蛋白酶抑制物-1（TIMP-1）在高氧肺损伤新生大鼠的肺组织中动态变化以及两者的相互关系。方法将足月新生大鼠在出生后，分别持续吸人90％～95％高氧或空气，于1、3、7、14、21d取肺组织进行HE染色，应用分光光度计比色法检测肺组织丙二醛（MDA）含量、免疫组化技术检测MMP-9和TIMP-1动态表达。结果病理观察高氧3d时出现炎症反应，7d时出现肺泡发育阻滞，最终纤维化；高氧3、7、14d后MDA含量高于空气组（P〈0．05，P〈0．01，P〈0．05）；MMP-9表达主要在上皮细胞胞浆，高氧3d时较空气组增强（P〈0．05）；TIMP-1表达主要在上皮细胞、内皮细胞和肺泡巨噬细胞胞浆，3d后各时间点的表达均高于空气组（P〈0．05，P〈0．05，P〈0．01，P〈0．01）；MDA含量与MMP-9、TIMP-1蛋白表达呈正相关（P〈0．05，P〈0．01）。结论高氧暴露后可能通过氧化应激上调MMP-9和TIMP-1表达引起基膜的破坏，从而导致毛细血管通透性的增加和以后呼吸道重塑的发生。     

α-平滑肌肌动蛋白在高氧肺损伤中的表达变化及意义

目的 探讨高氧暴露下大鼠肺损伤中肌成纤维细胞表面标志α-平滑肌肌动蛋白(α -SMA)的表达变化及意义.方法 将64只3周龄SD大鼠按随机数字表法分为正常对照组(置于空气中,吸入氧浓度0.21)和高氧暴露组(置于玻璃氧舱中,95％氧),每组于高氧暴露1、7、14、21d随机处死8只大鼠.苏木素-伊红(HE)染色观察肺组织病理改变,免疫组化法观察α -SMA在肺组织中的表达与分布,蛋白质免疫印迹法( Western blotting)检测肺组织α-SMA表达.结果 HE染色发现,早期高氧肺损伤时肺组织以炎症水肿表现为主,后期则以间质纤维增生为主.免疫组化结果显示,正常对照组α -SMA在细支气管上皮、肺泡表面及肺泡间隔上表达极为微弱;高氧暴露后随时间的延长α-SMA在肺泡表面及肺泡间隔上表达逐渐增强,以21d时最为明显.Western blotting检测发现,与正常对照组相比,高氧暴露1d、7d时肺组织α-SMA表达无明显差异(1.02±0.12比1.00±0.13,1.05±0.14比0.99±0.12,均P＞0.05),高氧暴露14d、21d时α-SMA表达明显增强(1.27±0.21比1.05±0.15,2.26±0.28比1.05±0.14,P＜0.05和P＜0.01).结论 大鼠高氧暴露后随时间延长,α-SMA在肺组织中的表达逐渐升高,肺纤维化逐渐加重,说明肌成纤维细胞在肺组织纤维化重构过程中起重要作用.     

高浓度氧对新生大鼠肺氧自由基损伤及其发育的影响

[目的]观察持续吸入高浓度氧后新生大鼠发育中肺的病理及肺组织内脂质过氧化物的变化,探讨高浓度氧对新生大鼠肺发育的影响.[方法]新生大鼠出生后分别在90%以上氧和空气中持续暴露,于d3、d7、d14、d21,动态观察肺组织病理学改变和胶原染色面积的变化以及肺组织8-异前列腺素F2α含量.[结果]与空气对照组比较,高氧组肺泡发育受阻,出现肺泡变大且结构简单化、肺泡数目减少等肺泡发育不良的慢性肺疾病病理表现,肺损伤逐渐加重,最终纤维化;胶原染色阳性面积于d7时高于对照组,随时间延长而逐渐增加;8-异前列腺素F2α含量d3时升高,d7时最高,以后下降但至d21仍高于对照.[结论]高氧对新生大鼠肺有明显损害,使其肺发育受阻,最终出现胶原增加的纤维化改变;氧化损伤可能是引起慢性高氧肺损伤的原因之一.     

地塞米松对高氧肺损伤大鼠肺组织基质金属蛋白酶及其组织抑制剂表达的影响

目的 观察地塞米松对高氧暴露大鼠肺组织中基质金属蛋白酶(MMPs)及其组织抑制剂(TIMPs)表达的影响,探讨地塞米松治疗高氧肺损伤的作用机制。方法 2周龄Wistar大鼠32只,随机分为空气组和高氧组(各16只)。高氧暴露7 d后,取两组大鼠各8只检测支气管肺泡灌洗液(BALF)蛋白含量和肺湿/干重比(W/D),并观察肺组织病理学改变。余16只大鼠行肺组织培养,空气组8只作为空气对照组,高氧组8只各设高氧对照组,高氧 地塞米松1×10-8、1×10-6和1×10-4mol/L组,培养24 h后用逆转录-聚合酶链反应(RT-PCR)检测肺组织中MMP-2、MMP-9、TIMP-1、TIMP-2 mRNA的表达。结果①与空气组相比,高氧组肺组织出现水肿、出血、炎性细胞浸润;BALF中蛋白含量、W/D明显增高。②高氧对照组MMPs、TIMPs mRNA表达和MMP-2/TIMP-2、MMP-9/TIMP-1比值较空气对照组明显增高。③地塞米松能剂量依赖性下调MMP-2、MMP-9 mRNA表达;对TIMP-1、TIMP-2 mRNA表达有一定程度的抑制效应;随地塞米松浓度的增加,MMP-2/TIMP-2、MMP-9/TIMP-1比值亦逐渐降低。结论 地塞米松下调MMPs mRNA表达,调节MMPs/TIMPs之间的失衡,可能是其减轻高氧肺损伤的机制之一。     

高氧对早产鼠肺泡Ⅱ型上皮细胞的影响及降钙素基因相关肽的保护作用

目的 观察高氧对早产鼠肺泡Ⅱ型上皮细胞(AECⅡ)的影响以及降钙素基因相关肽(CGRP)对AECⅡ的保护作用.方法 将原代分离培养的孕19 d早产鼠AECⅡ接种至6孔培养板,实验随机分为空气组、高氧组、高氧CGRP组、高氧CGRP受体拮抗剂组.空气组和高氧组分别置于体积分数为21%的空气和60%的氧气中暴露24 h;高氧CGRP组在暴露前加入CGRP;高氧CGRP受体拮抗剂组在高氧CGRP组基础上加入CGRP受体拮抗剂(CGRP 8-37).培养24 h后,用分光光度计测定各组丙二醛(MDA)、总抗氧化能力(TAOC)、超氧化物歧化酶(SOD)水平;用流式细胞仪检测活性氧(ROS)和细胞凋亡率;用逆转录-聚合酶链反应(RT-PCR)测定表面活性蛋白C(SPC)的mRNA表达.结果 与空气组比较,高氧组ROS、MDA水平及细胞凋亡率均显著增高,TAOC、SOD水平及SPC mRNA表达均显著降低(P均<0.01).与高氧组比较,高氧CGRP组细胞MDA、ROS水平及细胞凋亡率均显著下降;而TAOC、SOD水平及SPC mRNA表达均明显增高(P均<0.01).高氧CGRP受体拮抗剂组与高氧组各指标比较差异均无统计学意义(P均>0.05).结论 暴露于60%氧24 h可导致早产鼠AECⅡ发生氧化损伤,诱导细胞凋亡及SPC mRNA表达下降;而CGRP可部分减轻AECⅡ的氧化损伤,减少凋亡,促进SPC mRNA表达,对高氧损伤的AECⅡ起保护作用.     

不同时间高氧下小鼠肺组织中Bruton酪氨酸激酶的变化及意义

目的观察不同时间段高氧对小鼠肺组织中Bruton酪氨酸激酶(Btk)表达及活化的影响,初步探讨Btk在高氧所致急性肺损伤(HALI)中的作用机制。方法雄性昆明小鼠60只,建立高氧肺损伤模型(FIO2≥95%),随机分为五组:空气对照组、高氧暴露1 d组(H1 d组)、高氧暴露2 d组(H2 d组)、高氧暴露3 d组(H3 d组)和高氧暴露7 d组(H7 d组)。光镜下观察各组肺组织病理学改变,测定支气管肺泡灌洗液(BALF)的总蛋白含量(TP)和肺湿/干重比值(W/D),应用Western blot检测各组Btk、p-Btk表达变化,并对以上数据进行统计学分析。结果随着高氧暴露时间的延长,肺组织病理程度、W/D比值和TP含量均逐渐增加,与对照组相较,H2 d组、H3 d组与H7 d组差异有统计学意义(P<0.05),而对照组与H1 d组各项指标比较差异均无统计学意义(P>0.05)。高氧暴露各组中Btk和p-Btk的表达量与肺病理损伤程度呈时间依赖性,H2 d组、H3 d组与H7 d组的表达均明显高于对照组,差异有统计学意义(P<0.01),但H3 d组与H7 d组肺组织Btk和p-Btk表达差异无显著性(P>0.05)。结论随着高氧暴露的延长,小鼠肺损伤程度进行性加重,其病理形成可能与Btk的表达活化相关,并且主要在肺组织氧化损伤的早期阶段发挥作用。     

水通道蛋白5在高氧肺损伤中的表达及调节机制

目的探讨水通道蛋白5(AQP5)在高氧肺损伤中的表达及其地塞米松对AQP5的调节作用。方法2周左右Wistar大鼠64只,按随机数字表法分为空气对照组、高氧暴露3、7、14d组和相应的地塞米松干预组。高氧暴露组置于常压氧仓中(O2体积分数≥95%);空气对照组置于同室常压空气中(O2体积分数为21%);各地塞米松干预组在暴露于空气或高氧的同时,经腹腔注射地塞米松5mg·kg-1·d-1,连续3d。采用逆转录聚合酶链反应(RT PCR)和免疫组化方法观察AQP5的mRNA表达和分布变化,并与地塞米松干预后进行比较分析。结果AQP5主要表达在肺泡型上皮细胞及气道分泌上皮顶质膜;与空气对照组相比,高氧暴露不同时间后,AQP5特异性表达部位保持不变,但随暴露时间延长,AQP5表达呈逐渐减弱趋势,高氧暴露3、7和14d,AQP5mRNA较空气对照组均降低(P均<0.05)。与同期高氧暴露组比较,地塞米松干预后不同时间点AQP5mRNA表达均无明显变化(P均>0.05)。结论高氧肺损伤时AQP5表达降低,可能是高氧肺损伤肺水肿形成的原因之一;而未见地塞米松对高氧肺损伤AQP5的表达有调节作用。     

富氢生理盐水对新生SD大鼠高氧肺损伤白介素-8含量及病理的影响

目的观察富氢生理盐水对新生SD大鼠高氧肺损伤的预防作用。 方法将新生SD大鼠随机分为3组,空气对照组、高氧对照组、高氧＋氢水组。高氧对照组、高氧＋氢水组大鼠置于氧浓度为90%~95%的氧气箱中,高氧＋氢水组每日腹腔注射富氢生理盐水2次（10 ml/kg）,空气对照组、高氧对照组每日腹腔注射生理盐水2次（10 ml/kg）,高氧暴露后第1、3、7、10天分别测量各组白介素（IL）-8水平,并观察肺部病理切片。 结果与空气对照组对比,高氧对照组IL-8含量明显升高,且肺部病理切片出现肺出血、肺泡间隔变薄,并出现大量肺泡融合现象;与高氧对照组比较,高氧+氢水组IL-8含量明显降低,病理图示肺出血、肺泡融合明显减少。 结论富氢生理盐水可一定程度减轻高氧对新生SD大鼠的肺部炎症损伤。     

Adenovirus-mediated fibroblast growth factor 1 expression in the lung induces epithelial cell proliferation: consequences to hyperoxic lung injury in rats

High concentrations of oxygen can induce pulmonary toxicity and cause injury to alveolar epithelial and endothelial cells. The present study was performed to determine whether the potent epithelial and endothelial fibroblast growth factor 1 (FGF-1) protected against hyperoxia-induced lung injury. Recombinant adenovirus carrying the gene encoding human secreted FGF-1 (Ad. FGF1) increased the proliferation of lung epithelial cells in vitro. Ad.FGF1 or control vector with an empty expression cassette (Ad.V152) was administered intratracheally to Wistar rats. With Ad.FGF1 (10(9), 5 x 10(9), 10(10), or 5 x 10(10) viral particles [VP]), FGF-1 protein was found in bronchoalveolar lavage fluid 4 days postinfection at levels proportional to the viral dose and was detected in plasma after doses of 10(10) VP or more were administered. Histological examination of the lungs showed intense proliferation and apoptosis of alveolar and bronchial epithelial cells, with few inflammatory cells. The alveolar architecture returned to normal within 17 days. Rats pretreated with Ad.FGF1 (10(9) or 5 x 10(9) VP) 2 days before exposure to hyperoxia (95% O2) survived, whereas rats pretreated with Ad.V152 died within 3 days. In conclusion, adenovirus-mediated FGF-1 overexpression in the lungs causes epithelial cell proliferation and has beneficial effects in hyperoxic lung injury.     

Intratracheal instillation of keratinocyte growth factor decreases hyperoxia-induced mortality in rats.

Alveolar type II cell proliferation occurs after many forms of lung injury and is thought to play a critical role in alveolar epithelial repair. Keratinocyte growth factor/fibroblast growth factor 7 (KGF) has been shown to promote alveolar type II cell growth in primary culture and alveolar epithelial hyperplasia in vivo. In this study, we used immunohistochemical analysis to determine the intrapulmonary distribution and cellular localization of recombinant human KGF (rhKGF) instilled into the trachea of rats. 6 h after administration, immunoreactive KGF was observed within the lung parenchyma and along alveolar epithelial cell membranes. By 18-24 h, KGF was detected intracellularly in alveolar epithelial cells and intraalveolar macrophages. Immunoreactive KGF was not demonstrable 48 h after delivery or in lung sections from PBS-treated animals. Intratracheal instillation of 5 mg/kg rhKGF stimulated a marked, time-dependent increase in the alveolar type II cell specific labeling index to a maximum level of 33 +/- 3% 48 h after rhKGF administration compared with 1.3 +/- 0.3% after PBS instillation. In addition, this increase in type II cell proliferation in vivo was documented by flow cytometric analysis of isolated type II cells which revealed a nearly fivefold increase in the proportion of cells traversing through the S and G2/M phases of the cell cycle. To test the hypothesis that KGFs effects on type II cells in vivo might affect the response to lung injury, rats were treated with rhKGF and exposed to hyperoxia. Animals that received 1 or 5 mg/kg rhKGF exhibited dramatically reduced mortality (P < 0.001, for both doses). Survival for animals treated with 0.1 mg/kg rhKGF was not significantly different from either untreated rats or animals treated with heat-denatured rhKGF. The lungs of rhKGF-treated animals that survived hyperoxia exposure had minimal hemorrhage and no exudate within the intraalveolar space. These experiments established that intratracheal administration of rhKGF stimulated alveolar type II cell proliferation in vivo and reduced hyperoxia-induced lung injury in rats. Directed delivery of KGF to the lungs may provide a therapeutic strategy to preserve or restore the alveolar epithelium during exposure to hyperoxia or other injurious agents.     

高氧致大鼠急性肺损伤Toll样受体2和4的变化及意义

目的 探讨Toll样受体(TLRs)在高氧致急性肺损伤(ALI)发病过程中的作用.方法 将32只SD大鼠按随机数字表法分为空气对照组和高氧暴露24、48、72 h组,每组8只.分别于相应时间点活杀8只大鼠,取肺组织标本,测定肺湿/干重(W/D)比值并行肺组织病理评分,用实时荧光定量逆转录-聚合酶链反应(RT-PCR)测定肺组织TLR2和TLR4的mRNA表达,用蛋白质免疫印迹法(Western blotting)测定肺组织TLR2和TLR4的蛋白表达,用酶联免疫吸附法(ELISA)测定肺组织匀浆中白细胞介素-6(IL-6)含量.结果 各高氧暴露组肺W/D比值均较空气对照组明显增高(P均<0.01).高氧暴露48 h、72 h肺组织病理评分[(2.69±0.53)分,(3.94±0.62)分]均明显高于空气对照组[(0.41±0.38)分,P均<0.01].RT-PCR结果显示,高氧暴露组肺组织TLR2和TLR4 mRNA表达均明显高于空气对照组(0.67±0.15和0.63±0.19),并均于24 h达高峰(1.82±0.33,1.35±0.26,P均<0.05).Western blotting结果显示,高氧暴露组TLR2和TLR4蛋白表达均较空气对照组[(7.20±0.51)%和(14.26±0.19)%]明显增高,分别于48 h、72 h达峰值[(28.12±0.24)%,(81.35±0.82)%,P均<0.05].ELISA结果显示,高氧暴露组肺组织匀浆IL-6含量较空气对照组[(639.38±95.24)pg/L]明显增高,于72 h达高峰[(1 300.58±442.24)pg/L,P<0.05].结论 在高氧引起的ALI中,TLR2和TLR4在肺组织炎症启动和维持中起重要作用.     

Calcitonin gene-related peptide ameliorates hyperoxia-induced lung injury in neonatal rats

Therapies with prolonged exposure to high-concentration oxygen are common in the treatment of critical pulmonary and cardiac conditions in newborns. However, prolonged exposure to hyperoxia could result in lung damages and developmental disorders manifested as acute lung injury and bronchopulmonary dysplasia, respectively. Calcitonin gene-related peptide (CGRP) has been shown to have a broad regulatory effect on the respiratory system. In this study, we explored the protective effects of CGRP on the hyperoxia-induced lung damage. Newborn Sprague-Dawley rats were randomly divided into three groups: normoxia, hyperoxia, and hyperoxia with CGRP. Hyperoxia groups were exposed to 95% oxygen for 14 days and treated once every other day with saline or CGRP. Hyperoxia exposure reduced the survival rate to 73%, when compared with the 93% survival rate observed in the normoxia group. The survival rate was improved to 84% with CGRP treatment. Treatment with CGRP under hyperoxia significantly alleviated the hyperoxia-induced lung histomorphological changes and the increases in leukocyte counts and total protein levels in bronchoalveolar lavage fluid that reflect the pulmonary microvasular damages. CGRP treatment also restored the decreased activity of superoxide dismutase, while it decreased the increased level of malondialdehyde in the lung tissues. Importantly, CGRP treatment significantly decreased the magnitude of the hyperoxia-mediated increase in the expression levels of tumor necrosis factor-α mRNA and transforming growth factor-β 1 protein. In conclusion, the hyperoxia-induced acute lung injury is associated with both oxidative stress and inflammatory responses, and CGRP may ameliorate the hyperoxia-induced lung injury by down-regulating these processes.     

Protective effects of N-acetylcysteine and erdosteine on hemorrhagic shock-induced acute lung injury.

BACKGROUND: The drugs N-acetylcysteine and erdosteine were used to evaluate their protective effects in hemorrhagic shock-induced acute lung injury in an animal model. METHODS: Forty rats were used and randomly allocated into four groups (n=10). Animals in group III were fed with water containing 1 mg/dl erdosteine, and those in group IV were given 0.5 mg/dl N-acetylcysteine 3 days before the experiment. Group I was taken as the control and group II was taken as the hemorrhagic shock group. Hemorrhagic shock was initiated by blood withdrawal and reduction of the mean arterial pressure to 40 mmHg within 10 min via the right carotid artery. After a hypotensive period of 2 h, animals were resuscitated by transfusion of the shed blood and Ringer lactate in a volume equal to the shed blood. After a period of 1 h, blood samples were taken via the carotid artery. Bronchoalveolar lavage was performed to recover cells from the alveolar space with 40 ml of bronchoalveolar lavage fluid. Lung tissues were also resected to measure tissue malondialdehyde and L-gamma-glutamyl-L-cysteinyl-glycine levels with high performance liquid chromatography. The numbers of neutrophils and alveolar macrophages in bronchoalveolar lavage fluid were counted. RESULTS: Serum malondialdehyde levels were significantly higher in the shock groups (P<0.05), but there was no significant difference (P>0.05). Lung malondialdehyde levels were also significantly increased in the shock groups (P<0.05). In the erdosteine-applied group, tissue malondialdehyde levels were lower than in group II and the NAC-applied group (P<0.05). In the analyses of serum and lung tissue L-gamma-glutamyl-L-cysteinyl-glycine, the values of groups I, II and IV were found to be below the calibration graphics. The alveolar macrophage count was found to be the highest and the neutrophil count the lowest in group III when compared with the other groups in bronchoalveolar lavage fluid analyses (P<0.05). CONCLUSION: We may say that in the model of hemorrhagic shock-induced acute lung injury, it was found that erdosteine has a protective effect on lung tissue.