失血性休克鼠肺组织Toll样受体基因的表达

目的探讨单纯性失血性休克（无复苏）对肺组织中Toll样受体（TLR）mRNA表达的影响及意义。方法C57BL／6小鼠45只。随机分为失血组、脂多糖（LPS）组（阳性对照组。尾静脉注射LPS5mg／kg）、假手术组（阴性对照组）。每组15只。心脏穿刺复制失血性休克模型，在不同时间点取出肺组织。提取总RNA，通过逆转录-聚合酶链反应（RT—PCR）半定量方法检测肺组织TLR2 mRNA和TLR4 mRNA的表达水平。结果在失血性休克和LPS刺激后肺出现明显的中性粒细胞浸润、红细胞渗出。正常肺组织中有TLR2 mRNA、TLR4 mRNA表达；住失血性休克和LPS刺激后0、1、2、4和6h肺组织TLR2 mRNA、TLR4 mRNA表达均逐渐增加；而假手术组未发生明显改变。结论失血性休克后肺组织TLR2 mRNA、TLR4 mRNA表达增加与急性肺损伤（ALI）的发生有密切关系。除增强了机体非特异性免疫能力外，同时增加了宿主对随后各种刺激的易感性。过度表达的TLR2、TLR4可能造成组织、器官结构和功能损害。     

高渗氯化钠溶液复苏抑制失血性休克大鼠肺细胞凋亡的初步研究

目的 探讨高渗氯化钠溶液(HS)复苏对失血性休克大鼠肺细胞凋亡的影响及其意义. 方法 将23只SD大鼠制作成重度失血性休克模型,随机分为假手术组(Sham组,8只)、高渗氯化钠溶液复苏组(HS组,9只)和等渗盐水复苏组(NS组,6只),采用流式细胞仪FITC-AnnexinV/PI荧光染色法定量测定休克/复苏后各组大鼠肺组织细胞的凋亡情况,并加以比较和分析. 结果 在失血性休克/复苏后的早期阶段,HS组和NS组大鼠的肺组织细胞即有大量凋亡发生,其肺细胞凋亡率均明显高于Sham组,差异有统计学意义(P＜0.01).同时,NS组大鼠的肺细胞凋亡率则显著高于HS组,差异有统计学意义(P＜0.01). 结论 在重度失血性休克大鼠模型中,与等渗盐水复苏相比较,高渗氯化钠溶液复苏能显著抑制失血/复苏后肺细胞的凋亡,有助于减轻休克后急性肺损伤,这可能也是高渗氯化钠溶液复苏肺保护作用的重要机制之一.     

内毒素性休克大鼠肺组织糖皮质激素受体mRNA的表达

目的 探讨内毒素(LPS)性休克大鼠肺组织糖皮质激素受体(GR)mRNA的表达.方法 56只SD大鼠,随机(随机数字法)分IPS休克组(16只)、LPS+血管活性肠肽(vasosctive intestinal peptide,VIP)组(16只)、LPS+VIP+糖皮质激素(GC)组(16只)和对照组(8只).尾静脉注射LPS制作休克模型,尾静脉注射LPS 10 mg/kg后,分别于15 min内注射VIP 5 nmol/kg或VIP 5 nmol/ks+甲基强的松龙3 mg/kg,对照组注射等容量生理盐水,分别于沣射后6 h和24 h处死,留取肺标本,观察肺组织病理变化,RT-PCR榆测肺组织GR mRNA的表达.结果 (1)肺组织病理改变:LPS组见肺泡腔结构破坏、肺泡间隔增宽、炎性细胞浸润、出血、间质水肿,细胞器破坏,LPS+VIP组和IPS+VIP+GC组病变较轻.(2)GR mRNA的表达:注射LPS后6 h,LPS组和LPs+VIP组GR mRNA表达下降,与对照组相比,差异具有统计学意义(P＜0.05).LPS组下降较LPS+VIP组稍明显,但差异无统计学意义(P＞0.05).24 h GR mRNA表达恢复.LPS+VIP+GC组GR mRNA表达6 h增加,24 h GR mRNA表达更高(P＜0.05).结论 LPS致肺损伤时,肺组织GR mRNA的表达减少.VIP和GC可抵抗炎症反应、减轻肺损伤,其机制可能与增强GR mRNA的表达有关.     

失血性休克和内毒素二次打击肺损伤时转化生长因子-β1/smad2信号通路的变化

目的 观察失血性休克(HS)+内毒素二次打击致肺损伤时肺转化生长因子-β1(TGF-β1)/smad2信号通路的变化.方法 24只SD大鼠被随机分为假手术(Sham)组和HS组,每组12只.HS组建立未控制HS+内毒素二次打击模型,并按失血前期90 min、复苏期60 min、观察期210 min进行实验.监测各时间点平均动脉压(MAP)、心率、呼吸频率,实验结束后取血测定动脉血气,活杀大鼠取肺组织测定肺毛细血管通透性及肺湿/干重(W/D)比值,采用苏木素-伊红(HE)染色在光镜下观察肺组织病理学改变,用免疫组化法和逆转录-聚合酶链反应(RT-PCR)测定肺组织TGF-61的蛋白及mRNA表达,用蛋白质免疫印迹法(West-ern blotting)测定肺组织smad2蛋白表达.结果 与Sham组比较,HS组MAP自院前期60 min后明显降低,血乳酸(Lac)明显升高,pH值、动脉血氧分压(PaO2)、HCO-3、动脉血氧饱和度(SaO2)均明显降低,剩余碱(BE)负值增大,肺毛细血管通透性及W/D比值明显升高(P均＜0.01);HS组肺组织TGF-β1呈强阳性表达,主要分布于肺泡上皮、间质炎性细胞、肺泡腔内巨噬细胞和小支气管黏膜上皮细胞;TGF-β1 mRNA和smad2蛋白表达均较Sham组明显上调(P均＜0.01).结论 二次打击大鼠TGF-β1/smad2信号通路被激活,并与肺毛细血管通透性和肺损伤的严重程度密切相关,可能是HS后肺损伤的重要机制之一.     

肌内皮缝隙连接对失血性休克大鼠血管收缩反应的影响

目的 研究肌内皮缝隙连接（MEGJ）对失血性休克大鼠内皮依赖性和非依赖性血管收缩反应的影响。方法 56只SD大鼠按随机数字表法分为去甲肾上腺素（NE）组和杨梅黄酮组；NE组分为正常对照以及休克0、0．5、1和2h5个亚组；杨梅黄酮组分为正常对照以及休克0、0．5、1、2、3和4h7个亚组。各组取其肠系膜上动脉（SMA）制成血管环，分别测量在18α-甘草次酸（18α-GA）作用前后血管环对NE和杨梅黄酮反应性的变化。结果 SMA血管环对NE的反应性表现为：休克0h和0．5h组明显高于正常对照组和其他休克时间点组，休克1h和2h组明显低于正常对照组和休克0h和0．5h组；18α-GA对NE诱导的SMA血管环收缩反应性无明显影响。SMA血管环对杨梅黄酮的反应主要表现为：休克0、0．5、1和2h组明显高于正常对照组，于休克2h达最高点；休克3h和4h组明显低于正常对照组，运用18α-GA阻断MEGJ后，各组血管环的收缩反应性较18α-GA作用前明显下降，其中以休克1、2和3h组下降幅度明显大于其他组。结论 失血性休克后早期，内皮依赖和非依赖性的血管收缩反应均有不同程度代偿性增加，休克1h和2h表现为非内皮依赖性血管收缩反应下降，休克3h和4h表现为内皮依赖性血管收缩反应明显降低；MEGJ在休克后内皮依赖性血管收缩反应的变化中起重要调节作用。     

驱动压对肺内源性急性呼吸窘迫综合征的影响

目的探讨不同驱动压力对脂多糖诱导的肺内源性急性呼吸窘迫综合征（ARDS）的治疗作用及其机制。 方法40只雄性Sprague-Dawley大鼠分为对照组、急性呼吸窘迫综合征模型组（ARDS组）、机械通气低驱动压组（L组）、机械通气一般驱动压组（M组）、机械通气高驱动压组（H组）,每组各8只。气管内滴注脂多糖6 mg/kg复制ARDS动物模型,模型复制成功后对L组、M组及H组实施相应的机械通气策略4 h。比较5组大鼠动脉血氧分压（PaO₂）、二氧化碳分压（PaCO₂）、肺组织湿/干重比、肺泡灌洗液（BALF）中总蛋白、Ⅲ型前胶原（PCⅢ）、血清中白细胞介素6（IL-6）的表达水平以及肺组织病理形态学变化情况。 结果5组大鼠PaO₂、PaCO₂、肺组织湿/干重比、BALF中蛋白含量、血清IL-6、PCⅢ表达水平、塌陷肺泡所占比例以及膨胀肺泡所占比例比较,差异均有统计学意义（F= 25.054、5.316、14.306、84.940、93.379、41.983、49.343、123.433,P均< 0.05）。进一步两两比较发现,L组和H组PaO₂、肺组织湿/干重比、BALF中蛋白含量、血清IL-6以及塌陷肺泡所占比例与ARDS组比较,差异均有统计学意义（P均< 0.05）,H组PaCO₂表达水平和膨胀肺泡所占比例与ARDS组比较,差异均有统计学意义（P均< 0.05）,L组PCIⅢ表达水平较ARDS组显著降低（P < 0.05）;H组PaO₂、血清IL-6、PCⅢ表达水平、塌陷肺泡所占比例以及膨胀肺泡所占比例与ARDS组比较,差异均有统计学意义（P均< 0.05）。 结论在小潮气量通气下,较低的驱动压力能够改善脂多糖诱导的肺内源性ARDS大鼠的气体交换,减轻肺水肿,降低炎症反应;当驱动压过高时可能引起肺过度膨胀,甚至诱发肺损伤的发生。     

活血化瘀中药对内毒素性休克内皮细胞的保护作用

目的 :探讨活血化瘀中药对内毒素性休克大鼠肺微血管内皮细胞的保护作用。方法 :选 Wistar大鼠 ,随机平分为对照组、模型组 (L PS)、地塞米松治疗组 (Dex)和活血化瘀中药治疗组 (AMRS)。电镜观察内皮细胞的超微结构改变 ,用电脑图像分析系统进行形态计测及肺微血管通透性指数 (PMPI)和循环内皮细胞 (CEC)数量的测定。结果 :AMRS组与 L PS组比较内皮细胞厚度极明显减小 (P<0 .0 0 1) ,胞饮泡体密度、细胞表面破损线密度、PMPI及 CEC数量均有明显差异 (P<0 .0 1或 P<0 .0 5 )。 AMRS组与 Dex组比 ,上述大多数指标有显著差异 (P均 <0 .0 5 ) ,微血管内血小板聚集、纤维素沉着和白细胞粘附内皮细胞现象也明显减少。结论 :在内毒素性休克中 ,活血化瘀中药在超微结构水平上能够改善、修复受损的内皮细胞 ,证实对内皮细胞具有保护作用     

Angiotensin-converting enzyme inhibitor captopril prevents oleic acid-induced severe acute lung injury in rats

Lack of specific and efficient therapy leads to the high mortality rate of acute lung injury (ALI) and acute respiratory distress (ARDS). Recent evidence implies that angiotensin-converting enzyme (ACE) plays an important role in the pathogenesis of ALI. Pharmaceutical inhibitors of ACE have been used clinically for hypertension but not for ALI/ARDS yet. The objective was to study the effects of ACE inhibition with captopril on severe lung injury induced by oleic acid (OA) in rats. Oleic acid was intravenously injected into Sprague Dawley rats, followed by i.p. administration of captopril or saline control. Lung injury, endothelium damage and related molecules, and disturbance of coagulation were examined in comparison between the treated and the nontreated groups. An OA-induced ALI was featured with thickening of the alveolar septa, alveolar hemorrhage, and infiltration of inflammatory cells. Comparing with the nontreated OA group, the administration of captopril prevented the rats from OA-induced severe lungs injury, with a significantly lower lung injury score, less albumin content and infiltrated cells in the alveoli, decreased wet/dry weight ratio of the lung tissues, and improved lung function (PaO2 per fraction of inspired oxygen). Captopril also dramatically reduced the expression of intercellular adhesion molecule-1 in the lung tissue and in the circulating endothelial cells in the blood, indicating a protective effect on endothelial cells activation/damage. Moreover, captopril treatment led to a blockage of nuclear factor kappaB activation in lung tissues and to the recovery of the fibrinolytic disturbance. Thus, our data suggest that the inhibition of ACE with its clinically used inhibitor offers protective effects on ALI/ARDS, implying the potential for therapeutic option.     

肺复张后不同潮气量对急性肺损伤大鼠肺血管内皮舒张功能的影响

目的 观察肺复张与肺复张后不同潮气量对ALI大鼠肺内皮舒张功能的影响.方法 内毒素(LPS)静脉注射复制大鼠ALI模型.25只清洁级SD大鼠随机(随机数字法)分成5组,每组5只:对照组、ALI组、小潮气量(VT)组(LV组,VT 6 mL/kg)、SI+小VT组(SI+LV组,VT 6 mL/kg)、SI+常规VT组(SI+MV组,VT12mL/kg),SI(30 cmH2O)维持30 s,进行肺复张.应用不同潮气量联合肺复张监测呼吸功能和血流动力学,实验5 h后放血处死动物.观察肺组织病理形态改变和湿/干重比(W/D);放射免疫法检测肺组织中ET-1;免疫组织化学法半定量分析肺动脉内皮细胞内皮型一氧化氮合酶(eNOS)蛋白表达水平;血管张力实验检测离体肺动脉环对乙酰胆碱(Ach)和硝普钠(SNP)介导的舒张功能的影响;ELISA检测肿瘤坏死因子-α(TNF-α)炎症反应指标.结果 与CON组比较,LPS增加各组内肺水肿,加重肺损伤,增加TNF-α含量,增加ET-1含量,减少肺动脉内皮细胞eNOS蛋白表达,减弱Ach介导的内皮依赖的舒张功能,最终影响内皮功能.SI+LV组ET-1含量为(109.18±15.62)pg/mL,SI+MV组和LV组肺组织ET-1含量分别为(158.78±30.40)pg/mL和(152.35±8.21)pr/mL,较SI+LV组升高(P＜0.05);SI+LV组肺组织eNOS蛋白表达的iOD值为(12663.83±1348.93),SI+MV组和LV组肺组织eNOS蛋白表达的iOD值分别为(9208.12±2773.68)和(9339.53±3366.40),较SI+LV组无统计学差异,但有降低趋势(P＞0.05);与SI+LV组比较,ALI组和SI+MV组在不同浓度Ach作用下内皮依赖的舒张功能降低(P＜0.05),LV组虽然与SI+LV组比较差异无统计学意义,但Ach介导舒张功能有下降的趋势;SI+LV组肺组织TNF-α含量(2374.53±410.60)ng/L,较SI+MV组(3468.86±659.25)ng/L和LV组(3370.75±314.17)ng/L降低(P＜0.05).结论 肺复张联合大潮气量和小潮气量机械通气能够改善ALI大鼠肺血管内皮舒张功能,肺复张联合小潮气量可进一步减轻ALI大鼠肺血管内皮舒张功能的损伤.     

ICI174,864对失血性休克大鼠全身及局部血管反应性变化的作用

目的 观察大鼠不同程度失血性休克时全身和局部血管反应性变化及δ阿片受体特异性拮抗剂IC1174,864对失血性休克大鼠血管反应性的影响。方法 56只Wistar大鼠,戊巴比妥钠麻醉(30mg／kg)。实验分两部分。第一部分实验用32只大鼠,随机分为手术对照组、1h低血压组,2h低血压组和3h低血压组,每组8只动物;动物经股动脉插管放血至血压40mmHg(1mmHg=0．133kPa)分别维持1、2和3h,然后回输全部残余失血,观察回输血后1、2和3h血压和肠系膜上动脉(SMA)对去甲肾上腺素(NE,3pg,／kg)的反应性变化。第二部分实验用24只大鼠,随机分为失血性休克对照组、IC1174,864 0．5mg／kg干预组和1．0mg／kg干预组,每组8只动物;动物经股动脉插管放血至血压40mmHg,维持2h,回输残余失血,观察给予IC1174,864后1、2和4h血压和SMA对NE(3μg／kg)的升压和收缩反应。结果 失血性休克后全身(血压对NE的升压反应)和局部(SMA对NE的收缩反应)血管反应性显著降低,且呈一定的程度和时间依赖性,即休克程度越重,时间越长,血管反应性降低越多。单纯回输失血不能纠正血管的低反应性,IC1174,864对休克血管的低反应性有不同程度的恢复作用,且呈一定的剂量依赖关系。结论 失血性休克可诱导全身和局部血管反应性降低,并与休克程度和时间密切相关,全身和局部血管反应性的降低呈现一定的平行关系。δ阿片受体特异性拮抗剂IC1174,864对失血性休克大鼠的血管低反应性有一定的恢复作用。     

粘附分子和白介素8在早期急性呼吸窘迫综合征中的作用研究

目的 :探讨急性失血致低血容量性休克后低剂量内毒素动物模型中血浆白介素 8(IL 8)、细胞间粘附分子 1(ICAM 1)、血管内皮粘附分子 1(VCAM 1)水平的改变及其与血浆 IL 1β水平的关系。方法 :2 2只新西兰白兔随机分成 4组 :1低血容量性休克组 (休克组 ,6只 ) :急性失血持续 1小时 ,以心排血量低于基础值 40 %为准 ,休克恢复 6 0分钟后再观察 4小时 ;2内毒素 (L PS)组 (6只 ) :以 1.0 0～ 1.2 5μg/ kg L PS静注 ;3休克 L PS组 (6只 ) :低血容量性休克恢复 6 0分钟后再静注低剂量 L PS;4正常对照组 (4只 )。分别在休克前、休克 6 0分钟、休克恢复 6 0分钟、静注 L PS2和 4小时 5个点抽血测 IL 8、IL 1β、ICAM 1和 VCAM 1水平。结果 :休克 L PS组血浆 VCAM 1水平于注射 L PS4小时后显著高于正常对照组 (P<0 .0 5 ) ;血浆ICAM 1水平于注射内毒素第 2和 4小时后亦均高于正常对照组 (P均 <0 .0 5 ) ;休克组、休克 L PS组血浆IL 8浓度在注射 L PS后 2小时均显著高于正常对照组 (P均 <0 .0 5 ) ;休克组和休克 L PS组兔在休克期血浆 IL 1β浓度显著升高 ,而休克 L PS组于静注 1μg/ kg L PS后 2和 4小时 ,血浆 IL 1β浓度再次显著升高。结论 :低血容量性休克后再注射低剂量内毒素可导致血浆 ICAM 1和     

Effect of post recruitment maneuver ventilation by different tidal volume on lung vascular endothelial diastole function in rats with acute lung injury

BACKGROUND: This study aimed to observe the effect of recruitment maneuver (RM) and post-RM ventilation at different tidal volume on lung vascular diastole endothelial function in rats with acute lung injury (ALI).METHODS: A ALI rat model was produced by intravenous infusion of lipopolysaccharide (6 mg/kg). Twenty-five rats were randomly divided into five groups: control group (n=5), ALI group (n=5), low tidal volume group (LV group, VT 6 mL/kg, n=5), sustained inflation (SI) with low tidal volume group (SI+LV group, VT 6 mL/kg, n=5), and SI with moderate tidal volume group (SI+MV group, VT 12 mL/kg, n=5). RM was performed with SI, airway pressure 30 cmH₂O for 30 seconds, and positive end-expiratory pressure (PEEP) was set to 5 cmH₂O. Lung tissue was taken after 5 hours of mechanical ventilation. Mean arterial blood pressure (MAP) was monitored during the experiment. Endothelin-1 (ET-1), endothelial nitricoxide synthase (eNOS), Ach-induced endothelium-dependent relaxation response of isolated pulmonary artery rings were determined at 5 hours.RESULTS: LPS increased ET-1 level, decreased the expression of eNOS in lung tissue, impaired the Ach-induced endothelium-dependent relaxation response in the pulmonary artery, without obvious effect on systemic hemodynamics. SI+LV significantly reduced LPS-induced elevation of ET-1 level, increased the expression of eNOS, significantly improved endothelial dysfunction, and improved the dysfunction of endothelium-dependent relaxation in the pulmonary artery.CONCLUSIONS: RM with a high or low tidal volume ventilation could improve the lung vascular endothelial function of rats with acute lung injury, and RM with low tidal volume ventilation could lower significantly the injury of lung vascular endothelial diastole function in rats with acute lung injury.     

银杏叶提取物对人工衰老大鼠肺肾功能的保护作用

背景衰老大鼠静脉注射脂多糖后能导致肺损伤,进而发现随着肺损伤的进展,影响肾功能.银杏叶提取物具有一定的清除自由基、改善血液流变学和保护血管内皮细胞等功能. 目的研究人工衰老大鼠肺损伤后是否发生肾功能不全,以验证老年多器官功能不全的肺启动机制,并观察银杏叶提取物对其是否有保护作用. 设计以实验动物为观察对象的随机对照的实验. 单位中国协和医科大学基础医学研究所病理生理学系. 材料实验于2001-05/2003-01在中国协和医科大学基础医学研究所病理生理学系实验室完成.选用36只Wistar雄性大鼠. 方法给大鼠每天1次经腹腔注入D-半乳糖(50 mg/kg),连续6周,复制衰老动物模型,再随机分为3组对照组(静脉注射生理盐水);脂多糖组(静脉注射脂多糖,5 mg/kg);银杏叶提取物+脂多糖组(注射脂多糖前7 d开始,每天银杏叶提取物灌胃1次,31 mg/kg).各组大鼠在给生理盐水或脂多糖后2 h或6 h取血和肺、肾组织. 主要观察指标用比色法测定血中肌酐、尿素氮含量;血、肺、肾组织中丙二醛、No2-/NO3-含量及谷胱甘肽过氧化物酶及Na+-K+-ATP酶活性的测定. 结果衰老大鼠在注射脂多糖后2,6h时已形成急性肺损伤.注射脂多糖 后2 h血中肌酐及尿素氮含量无明显升高,而6 h时均显著升高,分别为 (94.7±10.3)μmol/L,(11.4±1.9)mmol/L.在注射脂多糖后2h,血和肺组织 中丙二醛[(22.5+2.6)nmol/L,(25.8±2.9)μmol/gl和No2-/NO3-含量[(58.5 ±6.8)mmol/L,(34.6±3.8μmol/g]均显著升高,而谷胱甘肽过氧化物酶 [(355.1±45.0)μkat/g]及Na+-K+-ATP酶[(886.3±97.1)nkat/g]下降.上述指标 的变化持续至观察的6 h.而肾组织中上述指标仅在注射脂多糖后6 h才 有显著性变化.银杏叶提取物可显著缓解上述指标的变化. 结论脂多糖所致衰老大鼠的肺损伤可进一步诱导肾功能受损.银杏叶 提取物对脂多糖诱发的衰老大鼠的急性肺损伤和由此诱导的肾功能受 损有明显的保护作用.     

大黄对急性肺损伤大鼠热休克蛋白70表达的影响

目的探讨脂多糖(LPS)致急性肺损伤(ALI)中热休克蛋白70(heatshockprotein,HSP)的表达以及大黄对ALI的保护作用机制。方法用Wistar大鼠复制ALI的动物模型,动物随机分成四组:对照组、ALI组、大黄预防用药组、大黄治疗用药组,每组15只。大黄采用腹腔注射给药,分别于注射LPS或生理盐水后2h处死动物。用HE染色观察组织病理学改变,对ALI组和大黄用药组测定肺系数和动脉血氧分压(PaO2),并应用免疫组织化学和蛋白印迹方法检测组织中HSP70的表达。结果ALI组肺间质水肿,肺泡腔内可见大量中性粒细胞浸润和血浆蛋白渗出,肺血管内皮细胞损伤。ALI组HSP70的表达量较少,大黄用药组HSP70表达量增强。大黄用药组肺系数测定明显降低,PaO2明显升高。ALI组肺系数测定升高,PaO2降低。结论大黄对ALI的肺组织起保护作用,并且预防组强于治疗组。大黄能增加LPS诱导ALI组织中HSP70的表达,表明大黄对ALI的肺组织起保护作用与HSP70相关。     

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。     

ASK1-p38 cascaded signal mediates pulmonary microvascular endothelial barrier injury induced by the return of PHSML in rats

The return of post-hemorrhagic shock mesenteric lymph (PHSML) induces pulmonary vascular endothelial barrier dysfunction, which results in acute lung injury. Activation of the apoptosis signal-regulated kinase 1 (ASK1) and p38 mitogen-activated protein kinase (p38 MAPK) pathway has been shown to trigger inflammatory responses. However, whether the ASK1-p38 MAPK pathway is involved in the PHSML-induced pulmonary endothelial barrier dysfunction remains unclear. In the present study, permeability changes of pulmonary capillaries were found in vivo, and activation of the ASK1-p38 MAPK pathway was determined in vitro. PMVEC barrier dysfunction was determined by measuring TEER. Furthermore, junctional and cytoskeletal protein expressions were analyzed. The results showed that hemorrhagic shock led to a marked increase in the permeability of pulmonary capillaries in vivo, which was markedly alleviated by PHSML drainage. In cultured pulmonary microvascular endothelial cells (PMVECs), PHSML reduced the endothelial barrier function accompanied by upregulated p-ASK1 and p-p38 MAPK protein expression, impaired the cytoskeletal protein structure, and down-regulated junction protein expression. These adverse effects were eliminated by applying either Trx1 (ASK1 inhibitor) or SB203580 (p38 MAPK inhibitor). These results indicated that the ASK1-p38 MAPK pathway mediates PHSML-induced pulmonary vascular endothelial barrier dysfunction during hemorrhagic shock.

The return of post-hemorrhagic shock mesenteric lymph (PHSML) induces pulmonary vascular endothelial barrier dysfunction, which results in acute lung injury.     

Glucocorticoid receptor expression on acute lung injury induced by endotoxin in rats

BACKGROUND:

In cases of severe sepsis and septic shock, a series of pathophysiological changes lead to multiple organ dysfunction syndrome. This study aimed to investigate the expression of glucocorticoid receptor mRNA in the rat lung following endotoxin (LPS) induced shock.

METHODS:

Totally 56 SD rats were randomly divided into 4 groups: LPS shock group (n=16), LPS+vasoactive intestinal peptide group(VIP) group, (n=16), LPS+VIP+ glucocorticoid (GC) group, (n=16),and control group (n=8). LPS shock was induced by intravenous injection of LPS (10 mg/kg) in rats. Within 15 minutes after LPS injection, rats in the treatment groups received VIP (5 nmol/kg) or VIP and methylprednisolone (3 mg/kg). The control group was given normal saline instead of LPS. The rats of the four groups were sacrificed at 6 hours,24 hours after injection respectively, and the lung tissues were collected. Pathological changes of the lungs were examined by light microscopy and electron microscopy. GRmRNA expression in the lung tissues was evaluated by RT-PCR.

RESULTS:

In the LPS shock group, lung histopathology demonstrated destruction of the alveolar space,widening of the inter-alveolar space, inflammatory cell infiltration and interstitial edema. However,pathological changes in the LPS+ VIP group and LPS+ VIP+GC group were milder than those in the LPS shock group. Six hours after LPS injection, GR mRNA expression was down-regulated in the LPS group (0.72± 0.24) and LPS+ VIP group (0.88±0.27) (P<0.05) as compared with the control group (1.17±0.22). The LPS shock group showed a more significant down-regualtion than the LPS+VIP group, but the difference was not statistically significant (P>0.05). In contrast, GRmRNA expression in the LPS+ VIP+GC group was significantly up-regulated at 6 hours and further at 24 hours (1.45±0.32 and 1.91±0.46 respectively) (P<0.05).

CONCLUSION:

GrmRNA expression decreased in LPS induced lung injury in rats. Combined treatment with VIP and GC mitigated lung injury ang inflammation. The mechanism may be related to up-regulation of GR mRNA expression.KEY WORDS: Glucocorticoid, GRmRNA, Vasoactive intestinal peptide, LPS, Shock, Inflammation, Lung injury, Rat     

Magnolol alters cytokine response after hemorrhagic shock and increases survival in subsequent intraabdominal sepsis in rats

Magnolol is a Chinese herb that has potent antioxidant effects. This study evaluated the effect of magnolol in the treatment of severe injury using a two-hit model in Sprague-Dawley rats. Hemorrhagic shock followed by resuscitation was performed. Intra-abdominal sepsis was induced by cecal ligation puncture. The rats were randomly segregated into the following three groups: group 1 (sham group) rats were sham-operated; group 2 (untreated group) rats received hemorrhagic shock and resuscitation and cecal ligation puncture 24 h later; and group 3 (treated group) rats were treated with magnolol and subjected to the same procedures as group 2. Plasma cytokine levels and tissue cytokine contents of lung, including tumor necrosis factor alpha (TNFalpha) and interleukin (IL)-10 were assayed after hemorrhagic shock and sepsis. Pulmonary injury study was performed using Evans blue dye and survival analysis was performed after development of sepsis. Plasma and tissue TNFalpha levels increased after hemorrhagic shock. Magnolol treatment blunted the TNFalpha levels in plasma and tissue. The plasma IL-10 level increased after hemorrhagic shock, whereas the tissue level of IL-10 did not change. Magnolol treatment did not alter the plasma level of IL-10 but did increase tissue level. After sepsis, TNFalpha levels in both plasma and tissue of magnolol-treated animals were significantly lower than those in untreated animals, whereas plasma and tissue IL-10 levels were not significantly different between treated and untreated groups. Pulmonary injury study showed that magnolol-treated rats had decreased pulmonary permeability after the onset of sepsis. Survival analysis showed that survival rate was significantly higher in the treated group. In conclusion, magnolol modifies the cytokine response after hemorrhagic shock and resuscitation; the proinflammatory cytokine response is suppressed. The modified cytokines response induced by magnolol may result in decreased tissue injury and increased survival in subsequent intra-abdominal sepsis.     

内毒素肺损伤小鼠肺内清道夫受体A表达的变化

目的 观察内毒素肺损伤发病中小鼠肺组织及肺泡巨噬细胞(AM)清道夫受体A(SR-A)表达的变化.方法 腹腔注射内毒素脂多糖(LPS)复制小鼠急性肺损伤模型,实验分为LPS致伤后0.5、1、2、4和8 h组及对照组,用小鼠AM株J774A.1细胞作体外实验,分为LPS作用后0.5、1、2、4和8 h组及无血清培养液对照组.用免疫组化及流式细胞仪观察分析小鼠肺组织及AM、J774A.1细胞的SR-A表达及分布.结果 LPS各组小鼠动脉血氧分压(PaO2)均明显低于对照组,且肺湿/干重(W/D)比值明显高于对照组(P均＜0.01).对照组小鼠肺组织除支气管上皮细胞、淋巴细胞无SR-A表达外,AM、肺血管内皮细胞、血管平滑肌细胞、肺泡上皮细胞、中性粒细胞胞膜及胞质均有SR-A表达.LPS致伤后0.5 h即可观察到肺组织SR-A免疫组化染色弱于对照组,并且随着致伤时间延长,染色逐渐变浅,表明内毒素肺损伤发病中肺内SR-A表达减少.用J774A.1细胞作体外实验也发现类似结果,以4 h和8 h组降低最为显著.流式细胞仪检测AM及J774A.1细胞的SR-A表达与免疫组化染色结果相符,且细胞膜SR-A下降较细胞总SR-A显著.结论 内毒素肺损伤小鼠肺组织及AM的SR-A表达减少,其表达变化可能与内毒素作用有关.