大黄对内毒素诱导急性肺损伤大鼠的保护作用

探讨脂多糖（LPS）致急性肺损伤（ALI）的作用机制及大黄的保护作用。用Wistar大鼠复制LL的的动物模型,观察组织病理学变化,测定ALI生物学指标及NO和iNOs。结果显示：LPS组肺间质水肿,肺泡腔内可见大量细胞润滑和血浆蛋白渗出;肺管内皮细胞损伤。肺湿干重比,肺泡灌洗液中中性粒细胞比例,蛋白含量及肺泡通透指数,肺毛细管通透性均显著升高,NO和iNOs也显著升高。地塞米松和大黄组,上述指标均较LPS组显著。LPS致LI的机制主要是直接损伤肺泡上和血管内皮细胞,大黄及地塞米松对血管内皮和肺泡上皮具有保护作用,其机制可能是通过抑制NO和iNOs活性实现。     

地塞米松对急性肺损伤中TREM-1表达的影响

目的　探讨地塞米松（Dexamethasone,Dex）对脂多糖（Lipopolysaccharide, LPS）诱导的急性肺损伤(acute lung injury, ALI)小鼠肺组织中髓样细胞表达的触发受体1（triggering receptor expressed on myeloid cells-1,TREM-1）表达的影响。 方法　以昆明小鼠为研究对象,腹腔注射LPS(10 mg/kg)建立ALI模型,30 min后给予不同浓度的Dex（5、10、20、40 mg/kg）处理6 h;选用Dex(10 mg/kg)处理不同的时间（6、12、24、36 h）。HE染色法观察肺组织病理损伤程度; RT-PCR检测肺组织TREM-1mRNA的表达;ELISA检测小鼠支气管肺泡灌洗液中可溶性TREM-1（sTREM-1）蛋白水平。 结果　Dex可减轻肺病理损伤;Dex呈时间依赖性地下调ALI小鼠肺组织的TREM-1 mRNA的表达,且在6 h即可降低;Dex呈剂量依赖地下调ALI小鼠肺组织中TREM-1 mRNA的表达,并在10 mg/kg时开始降低。Dex可降低ALI小鼠支气管肺泡灌洗液中sTREM-1的蛋白水平。 结论　Dex可呈剂量及时间依赖性下调ALI小鼠肺组织中的TREM-1mRNA的表达,并减少肺内髓样细胞胞膜TREM-1的脱落,提示Dex可能通过调节TREM-1的表达,从而抑制ALI早期的炎症级联反应,参与保护肺组织。     

Emphysema induced by elastase enhances acute inflammatory pulmonary response to intraperitoneal LPS in rats

Abnormalities in lungs caused by emphysema might alter their response to sepsis and the occurrence of acute lung injury (ALI). This study compared the extension of ALI in response to intraperitoneal lipopolysaccharide (LPS) injection in Wistar rats with and without emphysema induced by elastase. Adult male Wistar rats were randomized into four groups: control, emphysema without sepsis, normal lung with sepsis and emphysema with sepsis. Sepsis was induced, and 24 h later the rats were euthanised. The following analysis was performed: blood gas measurements, bronchoalveolar lavage (BAL), lung permeability and histology. Animals that received LPS showed significant increase in a lung injury scoring system, inflammatory cells in bronchoalveolar lavage (BAL) and IL‐6, TNF‐α and CXCL2 mRNA expression in lung tissue. Animals with emphysema and sepsis showed increased alveolocapillary membrane permeability, demonstrated by higher BAL/serum albumin ratio. In conclusion, the presence of emphysema induced by elastase increases the inflammatory response in the lungs to a systemic stimulus, represented in this model by the intraperitoneal injection of LPS.     

The Role of Endogenous Histamine on the Pathogenesis of the Lipopolysaccharide (LPS)-Induced, Acute Lung Injury: A Pilot Study

Abstract —Histamine is widely distributed in the lungs and increases capillary permeability and P-selectin expression. To observe the role of histamine in acute lung injury (ALI), we measured the histamine and protein concentrations and cell numbers in the bronchoalveolar lavage (BAL) of LPS-induced ALI in rats. We instilled LPS (3 mg/kg) intratracheally, in conjunction with the intravenous histamine receptor antagonists (mepyramine, a H1-receptor antagonist, or ranitidine, a H2-receptor antagonist). LPS increased protein concentration and neutrophil numbers in the BAL as well as myeloperoxidase (MPO) activity in lungs after 6 h. LPS also increased histamine concentration in BAL after 2 h. Mepyramine and ranitidine attenuated the increased histamine concentrations. Total cell number in the BAL and MPO activity in the lungs were significantly decreased and neutrophil numbers and protein concentration in the BAL seemed to decrease with the administration of ranitidine at 6 h. In conclusion, endogenous histamine might be involved in the recruitment of neutrophils and protein leaks in LPS-induced ALI via the H2 receptors.     

Tanshinone IIA ameliorates seawater exposure-induced lung injury by inhibiting aquaporins (AQP) 1 and AQP5 expression in lung

Aquaporins (AQPs), a family of transmembrane water channels, mediate physiological response to changes of fluid volume and osmolarity. It is still unknown what role of AQPs plays in seawater drowning-induced acute lung injury (ALI) and whether pharmacologic modulation of AQPs could alleviate the severity of ALI caused by seawater aspiration. In our study, the results from RT-PCR and Western blotting showed that intratracheal installation of seawater up-regulated the mRNA and protein levels of AQP1 and AQP5 in lung tissues. Furthermore, we found that treatment of tanshinone IIA (TIIA, one of the main active components from Chinese herb Danshen) significantly reduced the elevation of AQP1 and AQP5 expression induced by seawater in rats, A549 cells and primary alveolar type II cells. Treatment of TIIA also improved lung histopathologic changes and blood-gas indices, and reduced lung edema and vascular leakage. These findings demonstrated that AQP1 and AQP5 might play an important role in the development of lung edema and lung injury, and that treatment with TIIA could significantly alleviate seawater exposure-induced ALI, which was probably through the inhibition of AQP1 and AQP5 over-expression in lungs.     

Priming With Endotoxin Increases Acute Lung Injury in Mice by Enhancing the Severity of Lung Endothelial Injury

Endotoxin‐induced acute lung injury (ALI) is a commonly used model. However, the effect of a priming dose of endotoxin on lung fluid balance has not been well studied. We hypothesized that endotoxin‐induced ALI in mice would be enhanced under a priming condition. Mice were intratracheally (IT) instilled with either a priming dose of endotoxin from E. coli (0.5 mg/kg) or equal volume of PBS. Eighteen hours later, a larger challenge dose of endotoxin (5 mg/kg) was given IT. Control mice received PBS only. After 24 hr, the mice were sacrificed and the degree of lung injury and inflammation were measured. Endotoxin priming increased body weight loss and worsened hypothermia. Extravascular lung water and lung endothelial permeability were higher in the primed group. Priming with endotoxin reduced alveolar fluid clearance; however, there was no effect on bronchoalveolar lavage (BAL) levels of receptor for advanced glycation end products (RAGE). The primed group had increased alveolar inflammation as demonstrated by increased numbers of neutrophils in the BAL. There was no significant difference in NF‐κB p65 in the lung nuclear extract among the experimental groups. Taken together, priming with a small dose of endotoxin followed by a larger challenge dose of endotoxin induces more systemic illness and increased pulmonary edema in mice, largely due to increased lung endothelial permeability and lung inflammation. This model should be useful to investigators studying ALI who want to simulate the clinical setting in which more than one insult often leads to greater clinical lung injury. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.     

Comparative Study of Trans‐Oral and Trans‐Tracheal Intratracheal Instillations in a Murine Model of Acute Lung Injury

Animal model is of importance to further elucidate the pathogenesis of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). We envisioned a possibility that there might be the differences in lipopolysaccharide (LPS)‐induced acute lung inflammation by the trans‐oral and trans‐tracheal intratracheal instillations. We compared the LPS‐induced early inflammatory responses by these two methods. The evaluative system included bronchoalveolar lavage (BAL) fluid biochemical analysis and differential cell counting, lung wet/dry weight ratio and lung histology. In vitro studies were performed on human bronchial epithelial cell line NCI‐H292 and alveolar Type II epithelial cell line A549 stimulated with LPS. Both interleukin (IL)‐8 release in the BAL fluid and IL‐8 secretions from NCI‐H292 and A549 cells were measured. We found that the trans‐tracheal intratracheal instillation promoted the LPS‐induced cell injury, neutrophil infiltration, and pulmonary edema compared to the trans‐oral one. The LPS‐induced pathological changes by the trans‐oral intratracheal instillation were characterized by pulmonary interstitial edema, but the trans‐tracheal intratracheal instillation was exudative pulmonary edema. More IL‐8 is produced from A549 cells than from NCI‐H292 cells under the treatment of LPS. The increased IL‐8 release in the BAL fluid and enhanced inflammatory responses caused by LPS may be due to more LPS delivered into the alveolar spaces by the trans‐tracheal intratracheal instillation compared to the trans‐oral one. The trans‐tracheal intratracheal instillation is proved to be more suitable to establish the murine model of ALI than the trans‐oral one and helpful to further elucidate the pathogenesis of ALI/ARDS. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.     

气道给rhSOD对胎粪诱导肺损伤中NF-κB及MIP-1α表达的影响

目的：观察早期经气道给予重组人超氧化物歧化酶（rhSOD）对胎粪诱导大鼠肺NF-κB和炎症因子MIP-1α表达的影响，以探讨其在胎粪诱导肺损伤中的作用及其机制。 方法： 24只雄性SD大鼠，随机分为：（1）对照组（control）,经气管插管注入生理盐水1 mL/kg；（2）胎粪+生理盐水处理组（Mec/saline）；（3）胎粪+ rhSOD治疗组(Mec/rhSOD)。后两者先由气管插管注入20%新生儿胎粪生理盐水混悬液1 mL/kg建立急性肺损伤模型，再分别经气管插管注入生理盐水1 mL/kg或rhSOD 20 g·L-1·kg-1。24 h后取材， RT-PCR法测定肺组织MIP-1α mRNA、Western blotting法测定NF-κB蛋白表达改变，同时行支气管肺泡灌洗液（BAL）细胞计数。 结果： Mec/saline组大鼠BAL细胞计数、肺组织MIP-1α mRNA和NF-κB蛋白表达均明显高于control组［(4.68±1.40)×109 cells/L vs (0.53±0.19)×109 cells/L, 3.60±0.75 vs 1.56±0.33， 0.72±0.31 vs 0.23±0.21］，（均P<0.01）； Mec/rhSOD组大鼠BAL细胞计数、肺组织MIP-1α mRNA和NF-κB蛋白表达分别为(3.13±0.77)×109cells/L、2.20±0.39和0.44±0.21，均显著低于Mec/saline组（均P<0.01），但仍显著高于control组（均P<0.01）。 结论： 早期经气道给rhSOD可能通过抑制肺MIP-1α和NF-κB表达而减轻胎粪诱导的肺炎症反应。     

Vagal Efferent Fiber Stimulation Ameliorates Pulmonary Microvascular Endothelial Cell Injury by Downregulating Inflammatory Responses

Electrical stimulation of the vagus nerve may have positive effects on many inflammatory diseases. This study determined the beneficial effects of vagus nerve stimulation and the mechanisms by which it attenuates lipopolysaccharide (LPS)-induced acute lung injury (ALI). Rats were intraperitoneally injected with 10 mg/kg LPS to induce ALI. The results showed that vagus nerve stimulation could improve lung injury, as evidenced by remarkable reductions in lung edema (wet-to-dry weight ratio), neutrophil infiltration (myeloperoxidase activity), and pulmonary permeability [total number of cells and protein concentrations in bronchoalveolar lavage fluid (BALF)]. In addition, vagus nerve stimulation not only decreased the expressions of Src-suppressed C kinase substrate and E-selectin proteins in lung tissue but also effectively attenuated the concentrations of the proinflammatory cytokines tumor necrosis factor-α, interleukin-1β, and interleukin-6 in BALF. These suggest that vagus nerve stimulation is a suitable treatment for LPS-induced ALI and indicate that it helps ameliorate pulmonary microvascular endothelial cell injury by downregulating inflammatory responses.     

Protection of LPS-induced murine acute lung injury by sphingosine-1-phosphate lyase suppression

A defining feature of acute lung injury (ALI) is the increased lung vascular permeability and alveolar flooding, which leads to associated morbidity and mortality. Specific therapies to alleviate the unremitting vascular leak in ALI are not currently clinically available; however, our prior studies indicate a protective role for sphingosine-1-phosphate (S1P) in animal models of ALI with reductions in lung edema. As S1P levels are tightly regulated by synthesis and degradation, we tested the hypothesis that inhibition of S1P lyase (S1PL), the enzyme that irreversibly degrades S1P via cleavage, could ameliorate ALI. Intratracheal instillation of LPS to mice enhanced S1PL expression, decreased S1P levels in lung tissue, and induced lung inflammation and injury. LPS challenge of wild-type mice receiving 2-acetyl-4(5)-[1(R),2(S),3(R),4-tetrahydroxybutyl]-imidazole to inhibit S1PL or S1PL(+/-) mice resulted in increased S1P levels in lung tissue and bronchoalveolar lavage fluids and reduced lung injury and inflammation. Moreover, down-regulation of S1PL expression by short interfering RNA (siRNA) in primary human lung microvascular endothelial cells increased S1P levels, and attenuated LPS-mediated phosphorylation of p38 mitogen-activated protein kinase and I-κB, IL-6 secretion, and endothelial barrier disruption via Rac1 activation. These results identify a novel role for intracellularly generated S1P in protection against ALI and suggest S1PL as a potential therapeutic target.     

油酸-脂多糖介导大鼠急性肺损伤及肺组织AP-1活性的变化

本文探讨了在油酸－内毒素（OA＋LPS）介导的大鼠急性肺损伤（ALI）模型肺组织中，转录因子AP－1活性变化的意义。有用OA＋LPS序贯性两次致伤，复制ALI大鼠模型；采用凝胶迁移率分析法（EMSA）检测肺组织AP－1活性。结果显示：OA＋LPS模型组大鼠呼吸窘迫，PaO2早期低于8kPa，死亡率升高，肺含水量显著增加，肺水肿、浸润等病变严重，伴透明膜形成，肺组织AP－1活性显著升高；并且，间隔4h两次致伤后，P aO2降低幅度最大，死亡率高达78.57%，肺含水量最大，肺病理改变最重，肺组织AP－1活性最高。结果表明：OA＋LPS序贯性两次致伤，可以介导大鼠发生严重的ALI；ALI的发生、发展与AP－1活性异常升高有关。     

黑木耳多糖对内毒素诱导急性肺损伤大鼠肺组织的保护作用

目的:探讨黑木耳多糖对LPS诱导急性肺损伤大鼠肺组织的保护作用及其机制。方法:将健康SD大鼠随机分为对照组、LPS组、地塞米松组以及黑木耳多糖低、中、高浓度组,根据分组,分别给予生理盐水或不同浓度黑木耳多糖预防性灌胃7 d,第8天腹腔注射生理盐水或LPS(8 mg/kg),地塞米松组在给予LPS后腹腔注射地塞米松(3 mg/kg)。造模12 h后于腹主动脉取血,并制肺组织匀浆和肺泡灌洗液。检测支气管肺泡灌洗液中蛋白含量、肺湿/干重比、髓过氧化物酶(MPO)、总抗氧化能力(T-AOC)、总超氧化物歧化酶(T-SOD)、一氧化氮合酶(NOS)、丙二醛(MDA)等指标,做组织切片HE染色并进行肺损伤评分。结果:应用黑木耳多糖干预后,急性肺损伤大鼠支气管肺泡灌洗液中蛋白含量明显下降,肺湿/干重比值降低;大鼠肺组织中MPO、NOS活性及MDA含量较LPS组降低,T-AOC含量和T-SOD活性较之升高;肺组织病理改变减轻,肺损伤指数下降。结论:黑木耳多糖具有保护LPS损伤大鼠肺组织的作用,其机制可能与其抗氧化作用有关。     

活化蛋白-1和cAMP反应元件结合蛋白在脂多糖注射大鼠肺组织中的变化及地塞米松的影响

目的：探讨活化蛋白-1(AP-1)和cAMP反应元件结合蛋白(CREB)在急性肺损伤(ALI)发生发展中的可能作用，以及地塞米松的抗炎作用机制。方法： 采用脂多糖（LPS）5 mg/kg颈静脉注射复制ALI大鼠模型，用凝胶电泳迁移率改变分析法(EMSA)观察ALI大鼠肺组织AP-1和CREB的改变和地塞米松的影响。结果： ALI大鼠肺组织AP-1的DNA结合活性在2 h达到峰值，12 h后接近正常水平。CREB的活性在1 h即到达峰值，但直到12 h并未完全达到正常水平。地塞米松对AP-1和CREB的DNA结合活性均有显著抑制作用。 结论： AP-1和CREB可能在大鼠的急性肺损伤的发生中发挥重要作用，在转录水平的调节可能是糖皮质激素发挥抗炎作用的重要机制之一。     

Protective Effect of Resveratrol on Acute Lung Injury Induced by Lipopolysaccharide in Mice

Resveratrol, a phytoalexin found in a range of plant products, may exert a variety of pharmacological activities. In this study, we investigated the effect of resveratrol on acute lung injury (ALI) induced by lipopolysaccharide (LPS) in vivo, and we found that the pretreatment with resveratrol can effectively protect mice against LPS‐induced ALI. Mice were pretreated with 1 mg/kg resveratrol for 3 days before challenging with a dose of 15 mg/kg LPS. The histological result showed that resveratrol can suppress the edema, inflammatory cell infiltration, and alveolar structure damage of lungs in ALI mice, and a decrease in the lung W/D ratio was also observed in mice with resveratrol pretreatment. Additionally, resveratrol markedly decreased the production of inflammatory cytokines, including IL‐1β and MIP‐1α and prevented the release of nitric oxide (NO) through inhibiting the expression of inducible NO synthase in lung tissues. Furthermore, the pretreatment with resveratrol suppressed the nuclear translocation of NF‐κB in lung tissues, which may be partly responsible for its effect on the ALI. In conclusion, the results presented here may suggest resveratrol as a potential therapeutic agent for treating ALI in the future. Anat Rec, , 2011. © 2011 Wiley‐Liss, Inc.     

Delayed Resolution of Lung Inflammation in Il-1rn-/- Mice Reflects Elevated IL-17A/Granulocyte Colony-Stimulating Factor Expression

IL-1 has been associated with acute lung injury (ALI) in both humans and animal models, but further investigation of the precise mechanisms involved is needed, and may identify novel therapeutic targets. To discover the IL-1 mediators essential to the initiation and resolution phases of acute lung inflammation, knockout mice (with targeted deletions for either the IL-1 receptor-1, i.e., Il-1r1(-/-), or the IL-1 receptor antagonist, i.e., Il-1rn(-/-)) were exposed to aerosolized LPS, and indices of lung and systemic inflammation were examined over the subsequent 48 hours. The resultant cell counts, histology, protein, and RNA expression of key cytokines were measured. Il-1r1(-/-) mice exhibited decreased neutrophil influx, particularly at 4 and 48 hours after exposure to LPS, as well as reduced bronchoalveolar lavage (BAL) expression of chemokines and granulocyte colony-stimulating factor (G-CSF). On the contrary, Il-1rn(-/-) mice demonstrated increased BAL neutrophil counts, increased BAL total protein, and greater evidence of histologic injury, all most notably 2 days after LPS exposure. Il-1rn(-/-) mice also exhibited higher peripheral neutrophil counts and greater numbers of granulocyte receptor-1 cells in their bone marrow, potentially reflecting their elevated plasma G-CSF concentrations. Furthermore, IL-17A expression was increased in the BAL and lungs of Il-1rn(-/-) mice after exposure to LPS, likely because of increased numbers of γδ T cells in the Il-1rn(-/-) lungs. Blockade with IL-17A monoclonal antibody before LPS exposure decreased the resultant BAL neutrophil counts and lung G-CSF expression in Il-1rn(-/-) mice, 48 hours after exposure to LPS. In conclusion, Il-1rn(-/-) mice exhibit delayed resolution in acute lung inflammation after exposure to LPS, a process that appears to be mediated via the G-CSF/IL-17A axis.     

Protective Effect of Magnolol on Lipopolysaccharide-Induced Acute Lung Injury in Mice

Magnolol, a tradition Chinese herb, displays an array of activities including antifungal, antibacterial, and antioxidant effects. To investigate the protective effect of magnolol on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. ALI was induced in mice by intratracheal instillation of LPS (1?mg/kg). The mice received intratracheal instillation of magnolol (5???g/kg) 30?min before LPS administration. Pulmonary histological changes were evaluated by hematoxylin-eosin stain and lung wet/dry weight ratios were observed. Concentrations of tumor necrosis factor (TNF)-?? and interleukin (IL)-1??, and myeloperoxidase (MPO) activity were measured by enzyme-linked immunosorbent assay. Expression of cyclooxygenase (COX)-2 in lung tissues was determined by Western blot analysis. Magnolol pretreatment significantly attenuated the severity of lung injury and inhibited the production of TNF-?? and IL-1?? in mice with ALI. After LPS administration, the lung wet/dry weight ratios, as an index of lung edema, and MPO activity were also markedly reduced by magnolol pretreatment. The expression of COX-2 was significantly suppressed by magnolol pretreatment. Magnolol potently protected against LPS-induced ALI and the protective effects of magnolol may attribute partly to the suppression of COX-2 expression.     

Ang-2在大鼠内毒素性急性肺损伤中的作用

目的:探讨促血管生成素2 (Ang-2 )在不同程度急性肺损伤(ALI)中的作用.方法:清洁级SD大鼠共40只, 随机分为4组: 正常对照组, 不同剂量大肠杆菌脂多糖(LPS)组(3个剂量组: 2 mg/kg、 4 mg/kg及8 mg/kg), 每组平均10只.HE染色光镜观察肺组织标本病理改变并进行肺损伤评分, Western blot检测各组大鼠血浆中Ang-2的表达情况.结果:LPS可致肺泡间隔增宽、出血及大量炎性细胞浸润等急性肺损伤病理改变, LPS各组的肺损伤评分明显高于正常对照组(P<0.01);LPS不同剂量与肺损伤评分呈量效依赖关系(P<0.05).LPS不同剂量组的血浆中Ang-2蛋白表达较空白对照组增高(P<0.01), LPS不同剂量与Ang-2蛋白表达水平呈量效依赖关系(P<0.05).血浆中Ang-2的蛋白表达与肺组织炎症程度积分呈正相关(r=0.862, P<0.05).结论:Ang-2参与大鼠内毒素性急性肺损伤的病理过程, 且血浆Ang-2水平与急性肺损伤程度呈正相关.     

乌司他丁对急性肺损伤大鼠TNT-α和IL-10 mRNA及p38 MAPK表达的影响响

 目的 探讨乌司他丁(UTI)对脂多糖（LPS）诱导急性肺损伤（ALI）大鼠的保护作用及分子生物学机制。方法 Wistar大鼠随机分为对照组、模型组(LPS 5mg/kg,iv)和干预组(UTI 50000U/kg,iv),用Real time RT-PCR法检测肺组织TNF-α和IL-10 mRNA表达,用免疫组化染色和Western blot技术检测肺组织中p38 MAPK的表达。结果 模型组0.5、1和3hTNF-αmRNA的表达分别是对照组的78.55±18.99,128.74±34.79和12.29±1.32倍,UTI预后分别降至20.95±1.45（p<0.01）,58.15±11.01（p<0.01）和2.85±0.57（p<0.05）倍。模型组0.5、1和3hIL-10mRNA的表达分别是对照组的20.89±4.60,38.20±8.26和53.26±8.01倍,乌司他丁干预后分别升至66.77±11.18（p<0.05）,97.69±27.00（p<0.01）和128.62±42.30（p<0.01）倍。模型组p38 MAPK的表达在各个时点均明显升高,UTI干预后p38 MAPK的表达减弱(p<0.05)。结论 UTI通过调节细胞因子基因表达发挥其肺保护作用。p38 MAPK信号通路在UTI下调TNF-α mRNA的表达中发挥了作用。     

Effects of dexamthasone with different doses on aquaporin-4 in brain of intracerebral hemorrhage rats

Objective:To determine the relationship between the expression of aquaporin-4(AQP4) after intracerebral hemorrhage and dexamethasone treated. Methods:Collagenase Ⅶ was injected in caudate nucleus in a stereotaxis frame to establish the intracerebral hemorrhage(ICH) animal models. The intracerebral hemorrhage(ICH) rats were randomly divided into four groups: the sham group (group A), the ICH group(group B), low dosertreated group(group C), moderate dose group(group D) and high dose group(group E). The groups were respectively received an intraperitoneal dexamethasone injection with 1 mg/kg, 15 mg/kg, 30 mg/kg, twice a day for three days. The brain water content(BWC), the permeability of blood-brain barrier(BBB) and the expression of AQP4 were observed. Results:Both the BBB disruption and AQP4 expression decreased in treated groups, and the AQP4 expression had a dose-dependent manner in the dexamethasone treatment. And it seemed that low dose dexamethasone was in favor of brain swelling elimination, but the higher dosage had not similar effect. Conclusion:Dexamethesone may play a critical role on expression of AQP4 in the physiopathology of hemorrhagic edema.     

地塞米松对大鼠内毒素急性肺损伤肺泡灌洗液中白细胞介素-1β和肿瘤坏死因子-α含量的影响

目的 探讨地塞米松对大鼠内毒素（LPS）急性肺损伤（ALI）肺泡灌洗液中白细胞介素-1β（IL-1β）和肿瘤坏死因子-α（TNF-α）含量的影响.方法 将48只雄性SD大鼠随机分为正常对照组、急性肺损伤组（内毒素ALI模型组）、地塞米松干预组,每组16只.每组大鼠依据不同的观察时间点（以大鼠气管内滴注LPS的时刻为起始时刻后的1、2、4、8 h 4个时间点）分为4个亚组（n=4）.给予正常对照组气管内滴注0.9%氯化钠溶液 0.3 mL,10 min后股静脉注射0.9%氯化钠溶液 1 mL;急性肺损伤组气管内滴注LPS 0.2 mg/kg（溶于0.3 mL 0.9%氯化钠溶液）,10 min后股静脉注射0.9%氯化钠溶液 1 mL;地塞米松干预组气管内滴注LPS 0.2 mg/kg,10 min后股静脉注射地塞米松注射液3 mg/kg（溶于1 mL 0.9%氯化钠溶液）.各组于1、2、 4、8 h 4个时间点于心脏抽血检测动脉血氧分压（PaO2）;取肺组织进行肺湿/干质量比值（W/D）测定,并采用苏木精-伊红（HE）染色观察肺组织形态学变化;用酶联免疫吸附测定（ELISA）法检测肺泡灌洗液（BALF）中IL-1β和TNF-α的含量.结果 给予气管内滴注LPS后于1、2、4、8 h观察大鼠动脉血PaO2,急性肺损伤组、地塞米松干预组较正常对照组显著降低,两组PaO2均在4 h时达最低点,各时间点动脉血PaO2对比,地塞米松干预组均显著高于急性肺损伤组,差异均有统计学意义（P〈0.05）.在LPS致炎后1、2、4、8 h 4个时间点急性肺损伤组、地塞米松干预组各时间点W/D比值均较正常对照组显著增加,两组间比较地塞米松干预组较急性肺损伤组降低,差异具有统计学意义（P〈0.05）.病理形态学观察可见急性肺损伤组与地塞米松干预组均出现肺水肿、出血、炎性细胞浸润,而地塞米松干预组肺损伤程度较急性肺损伤组减轻.ELISA试验结果显示急性肺损伤组在气管内滴入LPS 1 h后BALF中IL-1β、TNF-α含量迅速升高,4 h时达峰值,地塞米松干预后IL-1β、TNF-α表达在相同时间点均较模型组显著降低,差异具有统计学意义（P〈0.05）;而正常对照组BALF中IL-1β、TNF-α在不同时间点无明显变化.结论 地塞米松可通过抑制内毒素性大鼠ALI肺组织中IL-1β、TNF-α的表达,改善呼吸氧合功能,减轻肺损伤.