甘氨酸对出血性休克大白鼠生存率的影响

目的　研究甘氨酸对出血性休克大白鼠生存率的影响并探讨机制。方法　大白鼠经动脉放血 ,造成出血性休克 ,随后用自体血和生理盐水回输进行复苏。复苏前大白鼠分成 3组 :假休克组 ,休克组和甘氨酸治疗组。结果　 (1)复苏后 72h ,休克组与甘氨酸治疗组的生存率分别为 2 0 0 %和 77 8% ,差异有显著意义 (P <0 0 5 )。 (2 )复苏后 18h器官取材显示 :休克组大白鼠的肺、肾等组织出现水肿、变性、炎性细胞浸润等 ,甘氨酸治疗组上述的病理改变明显减轻。 (3)复苏后 18h ,肌酸磷酸激酶、肌酐、谷丙转氨酶、谷草转氨酶、碱性磷酸酶检测 ,休克组明显升高 ,而甘氨酸治疗组只有轻度增高 ,差异有非常显著性意义 (P <0 0 1)。 (4)复苏后 2h ,肝脏分离培养的枯否细胞用内毒素刺激后 ,休克组细胞内Ca2 浓度和TNF α产量明显高于甘氨酸治疗组 ,差异有非常显著性意义 (P <0 0 1)。结论　甘氨酸通过抑制枯否细胞内Ca2 浓度升高和抑制TNF α的过度产生 ,降低机体全身炎症反应程度 ,减轻出血性休克大白鼠脏器的损伤和降低病死率。     

限制性液体复苏对失血性休克大鼠网状内皮系统的影响

目的探讨限制性液体复苏对失血性休克大鼠网状内皮系统的影响。方法60只SD大鼠制成未控制性重度失血性休克模型,随机分成对照组、NF组(无液体复苏组)、NS40组(限制性液体复苏组)和NS80组(常规大量液体复苏组),检测和比较休克复苏后各组存活大鼠肝脏枯否细胞和腹腔巨噬细胞的吞噬功能。结果重度失血性休克大鼠失血后150min存活率NF组、NS40组和NS80组比对照组明显提高,NS40组较NS80组显著改善(P0.05);NS40组大鼠肝脏枯否细胞和腹腔巨噬细胞的吞噬功能较NS80组明显改善(P0.05)。结论限制性液体复苏可以显著改善失血性休克大鼠的网状内皮系统的吞噬功能,提高大鼠的免疫功能,降低死亡率。     

TNF-α McAb对急性失血性休克大鼠肝脏的作用

目的探讨肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)在急性失血性休克大鼠肝损伤中的作用及TNF-α单克隆抗体的保护作用。方法将24只雄性SD大鼠随机均分为三组:对照组(A组)、休克+乳酸林格氏液复苏组(B组)和休克+TNF-α单克隆抗体复苏组(C组)。B和C组大鼠通过股动脉放血,制作急性失血性休克动物模型;B组用乳酸林格氏液复苏,C组用含TNF-α单克隆抗体(3mg/kg)的乳酸林格氏液复苏,而A组在同等条件下不进行失血。分别检测各组大鼠血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、TNF-α水平和肝组织中MDA、SOD含量,并在光镜和电镜下观察各组大鼠肝组织的病理变化。结果 B、C组大鼠血清ALT、AST、TNF-α水平和肝组织中MDA含量较A组升高,SOD含量降低;C组ALT(343.63±35.61)U/L、AST(748.75±49.76)U/L、TNF-α(99.38±13.16)pg/mL、丙二醛(26.33±1.30)nmol/mgProt较B组ALT、AST、TNF-α、MDA含量降低,C组肝组织中SOD含量(510.14±47.44)U/mgProt较B组升高;在光镜、电镜下观察,C组肝组织损伤较B组减轻。结论 TNF-α可能是急性失血性休克肝损伤的重要因子之一,使用TNF-αMcAb复苏可以减轻失血性休克时大鼠肝损伤,具有一定的保护作用。     

维生素C减轻失血性休克引起的大鼠肺树突细胞聚集及肺损伤

目的 探讨失血性休克对大鼠肺组织树突细胞聚集及肺损伤的影响,以及维生素C的保护作用.方法 SD大鼠(6～7周龄)42只,按数字随机法随机分为对照组、失血性休克2h、6h、24 h组及失血性休克+维生素C2h、6h、24 h组等7组,每组各6只.以股动脉放血法建立大鼠失血性休克模型.免疫组化和逆转录聚合酶链反应(RT-PCR)法检测肺组织树突细胞特异性细胞间粘附分子非整合素蛋白-3(DC-SIGN)表达情况.同时检测肺TNF-α、IL-6含量,髓过氧化物酶(MPO)活性,并进行肺损伤评分.结果 对照组肺中DC-SIGN蛋白表达很少,失血性休克组表达显著升高(P＜0.05),失血性休克后2h肺DC-SIGNmRNA含量就开始增高,休克后24 h仍呈升高趋势.失血性休克组大鼠肺TNF-α、IL-6 mRNA水平升高(P＜0.05),MPO活性增加(P＜0.05),病理损伤显著加重(P＜0.05).失血性休克大鼠在复苏前给予维生素C干预后,上述现象均减轻(P＜0.05).结论 失血性休克可能通过促进肺组织树突细胞聚集引起急性肺损伤.维生素C对这一过程有抑制作用.     

乌司他丁对失血性休克大鼠肝脏缺血再灌注损伤保护作用的研究

目的：探讨乌司他丁对失血性休克大鼠肝脏缺血再灌注损伤的保护作用及机制。方法：24只雄性Wista大鼠随机分为假手术组、生理盐水治疗组、乌司他丁治疗组,每组8只。建立大鼠失血性休克模型。乌司他丁治疗组,予以乌司他丁25000U·kg-1加入2mL生理盐水静脉推注,并完成液体复苏;生理盐水治疗组予以2mL生理盐水静脉推注,并完成复苏;假手术组,除不放血和输液外,其他处理与模型相同。观察3h后处死大鼠,取血液离心分离血浆检测肝功能指标、血清肿瘤坏死因子（TNF-α）;取肝右叶2块肝组织,1块用于肝组织病理改变和肝细胞凋亡观察;1块用于肝组织匀浆,离心取上清液进行肝组织MDA、SOD、髓过氧化物酶（MPO）检测。结果：失血性休克大鼠肝脏再灌注3h后,生理盐水治疗组肝组织发生了严重缺血再灌注损伤,肝细胞水样变,肝窦淤血变窄,间质大量炎性细胞浸润,而乌司他丁治疗组仅有轻度再灌注损伤。乌司他丁治疗组肝细胞凋亡、肝功能指标ALT、AST、血清TNF-α水平、肝组织MDA含量、MPO活性较生理盐水治疗组均有不同程度的减少（P〈0.05）,SOD活性较生理盐水治疗组升高（P〈0.05）。结论：乌司他丁对大鼠失血性休克再灌注后肝脏损伤具有保护作用,其机制可能与抑制中性粒细胞浸润、抑制氧自由基的形成、抗肝细胞凋亡相关。     

兴奋胆碱能抗炎通路对内毒素致心肌损害的保护作用

目的：研究兴奋胆碱能抗炎通路对内毒素引起大鼠心肌损害的保护作用。方法：① 内毒素休克模型[静注内毒素（LPS）10mg/kg]：设手术对照组、单纯LPS组、迷走神经切断（VC）＋LPS组和VC＋LPS＋迷走神经电刺激（VS）组,观察电刺激迷走神经对心肌组织炎症介质和心肌酶指标的影响。②内毒素血症模型（静注LPS5mg/kg）：设LPS＋电针非经非穴组、LPS＋电针足三里穴组、VC后注射LPS组和VC＋LPS＋电针足三里穴组,观察电针副交感神经相关穴位足三里穴对内毒素血症引起的心肌组织损伤的保护作用。各组大鼠均于注射LPS后2h处死,检测血浆肌酸磷酸激酶同工酶（CK-MB）活性和组织病理学改变,内毒素休克各组测定心肌组织肿瘤坏死因子-α（TNF-α）含量。结果：刺激迷走神经可明显降低内毒素休克大鼠心肌组织TNF-α含量;刺激迷走神经或电针足三里穴能显著降低LPS注射后2h大鼠血浆CK-MB活性,减轻心肌组织病理损害;切断迷走神经能显著减轻或消除电针足三里穴的作用,进一步升高血浆CK-MB活性,加重心肌组织损害。结论：刺激副交感神经激活胆碱能抗炎通路对内毒素血症和内毒素休克大鼠心脏具有不同程度的保护作用。     

不同类型液体复苏对创伤失血性休克大鼠复苏后血清中IL-8与TNF-α的影响

目的探讨不同类型复苏液及不同复苏方式对创伤失血性休克大鼠早期液体复苏后血清中白细胞介素-8(interleukin-8,IL-8)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)的影响。方法选择健康成年雄性SD大鼠64只(体质量400~550 g),采用摸球法随机分为4组:乳酸钠林格液限制性复苏组(晶体限制性复苏组)、羟乙基淀粉(盈源)限制性复苏组(胶体限制性复苏组)、浓氯化钠(7.5%氯化钠液)限制性复苏组(浓氯化钠限制性复苏组)及羟乙基淀粉(盈源)非限制性复苏组(胶体非限制性复苏组),每组16只大鼠。实验大鼠均于称重后行戊巴比妥钠腹腔注射麻醉,左侧颈动脉置管,右侧股动脉置管,动物模型制作采用股骨创伤骨折并放血法。受试大鼠创伤失血性休克状态维持1 h后开始复苏,分别于成功复苏后第2、6、12及24 h时抽取腹主动脉血清,然后分别处死大鼠,终止实验。采用固相夹心酶联免疫吸附法试剂盒检测各组大鼠血清中IL-8及TNF-α含量。结果复苏后第6 h时,各限制性复苏组大鼠血清中IL-8及TNF-α含量较复苏后第2 h时的相应指标均明显升高(P0.05),且均达最高峰,然后均开始下降;至复苏后第12 h时,各限制性复苏组大鼠血清中IL-8及TNF-α含量继续呈下降趋势(P0.05)。非限制性复苏组各时相点大鼠血清中IL-8及TNF-α含量均明显高于各限制性复苏组相应时相点对应的指标(P0.05);同时,晶体限制性复苏组各时相点大鼠血清中IL-8及TNF-α含量均明显低于其他2种复苏液限制性复苏组各时相点对应的指标(P0.05)。结论从本研究的初步研究结果来看,在创伤失血性休克大鼠的液体复苏过程中,限制性液体复苏对大鼠休克状态的恢复要明显优于非限制性液体复苏;晶体复苏液相比胶体及浓氯化钠两种复苏液更能有效地抑制大鼠血清中IL-8和TNF-α的释放。     

失血性休克大鼠输注6%羟乙基淀粉对网状内皮系统功能的影响

目的 观察6％羟乙基淀粉（HES 200／0．5）用于纠正大鼠失血性休克对网状内皮系统功能的影响。方法 30只Wistar大鼠随机分为HES组和对照组（低分子右旋糖酐组）各15只。放血至平均动脉压5.33kPa(1kPa=7.5mmHg)，并用回输或放血方法维持该血压60min，复制失血性休克模型。输入与出血量相同体积的HES或低分子右旋糖酐，分别在复苏后12h(T1)、24h(T2)、48h（T3）、72h(T4)4个时间点，每个时间点分离、纯化3只大鼠肝脏枯否氏细胞（KC）计数KC吞噬Latex 乳胶颗粒的数量。结果 在同一时间点，HES组与低分子右旋糖酐KC吞噬功能无显著性差异；两组输液后任一时间点与T0（未经过休克及复苏，且未输注任一液体）点KC吞噬功能相比无显著性差异。结论 在机体失血量达血容量的20％－30％时输注相同体积的羟乙基淀粉溶液，对肝脏KC吞噬功能无显著影响。     

不同液体腹腔复苏对失血性休克大鼠肠道炎性反应的影响

目的 探讨不同液体腹腔复苏对失血性休克大鼠肠道炎性反应的影响.方法 清洁级健康雄性SD大鼠50只,体重200～250 g,随机分为5组(n=10):假手术组(S组)仅行手术操作,不制备失血性休克模型;采用股动脉置管放血法制备大鼠失血性休克模型,常规静脉复苏组(CVR组)失血性休克1 h后,经左侧股静脉匀速回输自体血及相当于2倍失血量的生理盐水行常规静脉复苏;不同液体腹腔复苏组(DPR1～3组)行常规静脉复苏,同时分别腹腔输注生理盐水、6%羟乙基淀粉130/0.4、2.5%腹膜透析液20 ml行腹腔复苏.输注时间均为30 min.右颈总动脉连接多功能监测仪持续监测平均动脉压;于复苏后2 h时股动脉采血,测定乳酸浓度,取小肠组织检测髓过氧化物酶(MPO)活性,采用免疫组化法检测小肠组织肿瘤坏死因子α(TNF-α)表达水平,光镜下观察小肠黏膜组织形态,计算小肠黏膜上皮损伤指数.结果 与S组比较,其余各组大鼠复苏后平均动脉压差异无统计学意义(P>0.05),动脉血乳酸浓度、小肠组织MPO活性、TNF-α表达水平及小肠黏膜上皮损伤指数升高(P<0.05或0.01);与CVR组比较,DPR3组动脉血乳酸浓度、小肠组织MPO活性、TNF-α表达水平及小肠黏膜上皮损伤指数降低(P<0.05).结论 采用2.5%腹膜透析液20 ml行腹腔复苏可有效抑制肠道炎性反应,从而对失血性休克大鼠产生保护作用.     

转录因子Egr-1在失血性休克复苏后肝脏损伤中的作用

目的研究转录因子Egr-1在失血性休克复苏（HS/R）后肝脏损伤中的作用.方法利用Egr-1野生型（WT）和基因封闭型（KO）小鼠复制失血性休克复苏模型.取肝组织,RT-PCR法测定肝组织中TNF-α、IL-6、G-CSF、ICAM-1 mRNA的表达变化.通过检测肝组织中MPO的含量、血清ALT水平和组织学检查,评估肝脏炎症细胞浸润和损伤程度.结果失血性休克2.5 h＋复苏4 h后,Egr-1 KO小鼠肝组织中TNF-α、IL-6、G-CSF、ICAM-1 mRNA的表达水平明显低于Egr-1WT组;Egr-1 KO组失血性休克复苏后肝组织炎性浸润和损伤程度减轻,表现为血清ALT水平低,肝组织中MPO含量低,病理损伤轻.结论本实验结果表明转录因子Egr-1参与了失血性休克复苏后肝脏炎症反应基因表达的调节,在失血性休克复苏后的肝脏损伤中起一定的作用.     

Mechanism of macrophage injury following traumatic hemorrhagic shock：through PTX—sensitive G—protein—mediated signal transduction pathway

OBJECTIVE: To study the mechanism of macrophage injury after trauma-hemorrhagic shock. METHODS: Wistar male rats underwent trauma (closed bone fracture) and hemorrhage (mean arterial blood pressure of 35 mm Hg+/-5 mm Hg for 60 minutes, following fluid resuscitation). Rats without trauma, hemorrhage or fluid resuscitation served as controls. Peritoneal macrophages were harvested at 6 hours and 1, 2, 3, 7 days after traumatic hemorrhagic shock to determine the effects of pertussis toxin (PTX, as a specific inhibitor to Gi(alpha) and cholera toxin (CTX, as a stimulant to Gs(alpha) on macrophage-Ia expression and TNF-alpha production and levels of Gi(alpha) and Gs(alpha). RESULTS: The macrophages from the injured rats revealed a significant decrease of Ia positive number and TNF-alpha release in response to LPS. Wi th pretreatment with PTX 10-100 ng/ml Ia positive cells and LPS-induced TNFalpha production in both control and impaired macrophages populations were dos e dependently increased. Both macrophages populations were not responding to CTX treatment (10-100 ng/ml). Western blot analyses showed that the levels of Gi(alpha) protein expression increased as much as 116.5%-148.8% of the control level fro m 6 hours through 7 days after traumatic hemorrhage. The levels of Gs protein expression were reduced at 6 hours and decreased to the lowest degree; 36% o f the control at day 1, began to return at day 2 and returned to the normal level at day 7, following traumatic hemorrhagic shock. CONCLUSIONS: PTX-sensitive G-protein may participate in th e modulation of macrophage-Ia expression and TNF-alpha release following traumatic hemorrhagic shock. Analyses of the alteration of Gi(alpha) and Gs protein express ions further supports the concept that G-protein is involved in trauma-induced macrophage signal transduction pathways.     

Heat shock response inhibits NF-kappaB activation and cytokine production in murine Kupffer cells

BACKGROUND: Kupffer cells play a crucial role in the pathogenesis of sepsis through production of proinflammatory mediators and control of systemic endotoxemia. The anti-inflammatory effects of heat shock response (HSP) have been well documented. However, the role of HSP in lipopolysaccharide (LPS) induced Kupffer cell activation has not been fully investigated. In this study, we investigated the effects of HSP on LPS induced Kupffer cell NF-kappaB activation and cytokine production. MATERIALS AND METHODS: Kupffer cells were isolated from mice by collagenase digestion and HSP was induced by culturing Kupffer cells with sodium arsenite. Kupffer cells were stimulated in vitro by LPS. Heat shock protein (HSP)-70 expression and cytoplasmic IkappaBalpha protein was determined by Western blot. Supernatant tumor necrosis factor (TNF)-alpha, interleukin (IL)-6 and IL-10 levels were measured by ELISA. NF-kappaB activation was analyzed by electrophoresis mobility shift assay. Cytokine and IkappaBalpha mRNA expression were determined by RT-PCR. Toll-like receptor 4 expression on Kupffer cells was determined by flow cytometry. RESULTS: HSP pre-conditioning significantly inhibited LPS-induced cytokine TNF-alpha and IL-6 production and mRNA expression. NF-kappaB activation and IkappaBalpha degradation induced by LPS were attenuated by HSP. HSP up-regulated expression of IkappaBalpha mRNA. No effect of HSP on cell surface expression of TLR4 was observed. CONCLUSIONS: Increased IkappaBalpha stability and up-regulation of IkappaBalpha gene expression may be one of the mechanisms of the inhibition of LPS induced Kupffer cell activation by HSP. HSP also inhibited expression of the anti-inflammatory cytokine IL-10, and the mechanism and biological significance of this effect merit further investigation.     

甘氨酸抑制脂多糖介导的鼠枯否细胞激活的时相选择及机制探讨

目的探讨甘氨酸抑制脂多糖介导的鼠枯否细胞激活效应相关机制和甘氨酸的最佳用药时机。方法将40只BALB/c小鼠分为内毒素组、预防组、早期治疗组和后期治疗组,每组10只。分离培养枯否细胞后,内毒素组加入脂多糖(10mg/L),预防组、早期治疗组和后期治疗组分别在加入脂多糖前24h、加入后0和4h加入甘氨酸(1mmol/L),分别在加入脂多糖后0、1、2、6和12h,采用逆转录聚合酶链反应及蛋白印迹法测定枯否细胞的白细胞介素1受体相关激酶4(IRAK4)mRNA和蛋白表达水平,用酶联免疫吸附法检测枯否细胞的核因子κB(NFκB)活性和培养上清液的肿瘤坏死因子α(TNFα)含量。结果脂多糖刺激后,预防组的IRAK4mRNA和蛋白表达、NFκB活性的相对峰值分别为3.64±1.13、34.54±10.31、0.47±0.10,TNFα峰值为(1780.70±210.17)pg/ml,与早期治疗组比较,差异均无统计学意义,但与内毒素组和后期治疗组比较,各峰值均明显降低,差异有统计学意义。结论提前或者在脂多糖刺激的同时应用甘氨酸,能有效抑制脂多糖介导的枯否细胞激活效应,其作用机制之一可能为抑制IRAK4的表达。     

Protective effects of medium-chain triglycerides on the liver and gut in rats administered endotoxin

OBJECTIVE: To determine if medium-chain triglycerides (MCTs) prevent organ injuries and mortality in rats administered endotoxin and to investigate effects of MCT on the gut. SUMMARY BACKGROUND DATA: Since dietary MCTs prevent alcohol-induced liver injury by inhibiting activation of Kupffer cells in the enteral feeding model, the authors hypothesized that MCT could prevent deleterious conditions in endotoxemia. METHODS: After a preliminary experiment determined the optimal dose of MCT, rats were given MCT (5 g/kg per day) or the same dose of corn oil by gavage daily for 1 week. Then, lipopolysaccharide (LPS) was administered intravenously and survival was assessed for the next 24 hours. For analysis of mechanisms, rats were killed 9 hours after LPS injection and serum and liver sections were collected. To investigate effects of MCT on the gut, pathologic change, permeability, and microflora were assessed. Kupffer cells isolated by collagenase digestion and differential centrifugation were used for endotoxin receptor CD14 immunoblotting, phagocytic index, and TNF-alpha production assay. RESULTS: All rats given corn oil died after LPS administration; however, this mortality was prevented by MCT in a dose-dependent manner. Rats given corn oil showed liver injury after LPS administration. In contrast, MCT prevented this pathologic change nearly completely. MCT blunted CD14 expression on the Kupffer cells and TNF-alpha production by isolated Kupffer cells; however, there were no differences in phagocytic index between the two groups. The length of the intestinal epithelium was increased in the MCT group compared to the corn oil group. Further, after LPS administration, increases in gut permeability and injury were prevented by MCT. Importantly, MCT also prevented hepatic energy charge and gut injuries in this condition. CONCLUSIONS: Enteral feeding using MCT could be a practical way of protecting the liver and intestine during endotoxemia.     

Rapid endotoxin-induced alterations in myocardial calcium handling: obligatory role of cardiac TNF-alpha.

BACKGROUND: Bacterial endotoxin (lipopolysaccharide [LPS]) induces septic shock and depressed myocardial contractility. The mechanism of LPS-mediated cardiac dysfunction remains controversial. We hypothesized that LPS exerts significant effects on myocardial excitation-contraction coupling by rapid stimulation of tumor necrosis factor alpha (TNF-alpha) expression in the heart. METHODS: Isolated rat hearts were studied with and without recirculation of cell-free perfusate. The effects of LPS, exogenous TNF-alpha, anti-TNF-alpha antibody, and ceramidase inhibition were examined. Measurements included myocardial uptake of LPS, left ventricular contractility, myocardial oxygen consumption, intracellular calcium [Ca2+] cycling, and TNF-alpha concentrations in coronary perfusate and myocardium. RESULTS: Lipopolysaccharide was rapidly taken up by the perfused heart. With non-recirculating perfusion, LPS had no effect on contractility, oxygen consumption, coronary vascular resistance, or intracellular free calcium concentration ([Ca2+]i). However, with recirculating perfusion contractility was significantly impaired after 30 min of LPS, associated with lower [Ca2+]i levels and attenuated systolic rise in [Ca2+]i. Significant amounts of TNF-alpha accumulated in recirculating perfusate and myocardial tissue from LPS-perfused hearts. Ceramidase inhibition or neutralizing anti-TNF-alpha antibody inhibited the effects of LPS on contractility and [Ca2+]i. Recombinant rat TNF-alpha mimicked the LPS effects with faster onset. CONCLUSIONS: Lipopolysaccharide exerts rapid, negative inotropic effects on the isolated whole rat heart. The reduction in contractility is associated with depressed intracellular calcium cycling. In response to LPS, TNF-alpha is rapidly released from the heart and mediates the effects of LPS via the sphingomyelinase pathway. The present study for the first time directly links LPS-stimulated TNF-alpha production, abnormal calcium cycling, and decreased contractility in intact hearts.     

p38丝裂原活化蛋白激酶信号转导通路在严重烧伤大鼠枯否细胞肿瘤坏死因子α和白细胞介素1β产生中的作用

目的 探讨p38丝裂原活化蛋白激酶(MAPK)信号转导通路在严重烧伤大鼠枯否细胞(KCs)促炎性细胞因子肿瘤坏死因子α(TNF-α)和白细胞介素1β(IL-1β)产生中的作用。方法 健康成年的雄性SD大鼠32只,随机分为：假烫组;假烫 SB203580组;烧伤对照组;烧伤 SB203580组,每组8只。假烫或烧伤24h后分离出肝脏KCs,培养18h后加入50ng／ml的LPS进行刺激,18h后取上清液,用酶联免疫吸附法(ELISA)测定TNF-α和IL-1β的含量,并收集KCs,实时逆转录聚合酶链反应检测KCs内TNF-α和IL-1β mRNA表达的改变,蛋白印迹(Western blot)法检测KCs中p38MAPK和JNK活性的变化。结果 烧伤大鼠分离出的KCs培养上清液中TNF-α和IL-1β含量、KCs中TNF-α和IL-1β mRNA的表达均较假烫组的明显增强,同时KCs中p38 MAPK活性和JNK活性升高,SB203580能显著抑制大鼠KCs上清液中TNF-α和IL-1β含量、KCs中TNF-α和IL-1β mRNA的表达和p38MAPK活性的升高,对JNK活性无影响。结论p38MAPK信号转导通路介导了严重烧伤大鼠KCs促炎性细胞因子TNF-α和IL-1β的产生。     

Organ interactions in sepsis. Host defense and the hepatic-pulmonary macrophage axis

Endotoxin (lipopolysaccharide [LPS]) and tumor necrosis factor (TNF-alpha) have been implicated in the pathogenesis of sepsis-induced adult respiratory distress syndrome. To evaluate the possible interaction of the hepatic-pulmonary macrophage axis in the adult respiratory distress syndrome, we compared the kinetics of immunosuppressive prostaglandin E2, TNF-alpha, and interleukin 6 production in LPS-stimulated Kupffer cells and alveolar macrophages (AMs). Interleukin 6 production by Kupffer cells was significantly higher than for equal numbers of AMs. Kupffer cell TNF-alpha levels peaked early before decreasing as regulatory prostaglandin E2 levels rose. In contrast, AM TNF-alpha levels rose sharply and remained significantly higher than for Kupffer cells throughout culture coincident with negligible prostaglandin E2 production. Kupffer cell sequestration of LPS may normally invoke a coordinated cytokine response able to locally induce acute-phase hepatocytes. In hepatic failure, however, LPS spillover to the lung may promote adult respiratory distress syndrome by inducing unregulated AM TNF-alpha production within the pulmonary microenvironment.     

Hepatic integrity dependent on matrix metalloproteinase inhibition, not tumor necrosis factor alpha or different bleeding rates

Discrepancies in the levels of proinflammatory cytokines such as tumor necrosis factor alpha (TNF-alpha) following hemorrhagic shock (HS) may be due to the inconsistent rates of bleeding. The purpose of this study was to investigate the effects of rapid versus slow bleeding rates on TNF-alpha levels and if inhibition of TNF-alpha convertase by a matrix metalloproteinase inhibitor (MMPI) affects hepatic integrity in animals exposed to 35% HS. Sprague-Dawley male rats (n = 24, 300-350 g) were divided into four groups: HS 15 (produced over 15 min), HS 30 (produced over 30 min), and HS with MMPI (2.5 mg/kg British Biotech 1101: HS15 + MMPI, HS30 + MMPI). Mean arterial blood pressure (MAP), serum TNF-alpha,levels, and hepatic resting membrane potentials (E(m)) were obtained. A Student t test was performed. TNF-alpha levels for HS 15, HS15 + MMPI, HS 30, and HS 30 + MMPI were 474, 40, 32, and 50 pg/ml, respectively. The hepatic resting membrane potentials for HS 15, HS15 + MMPI, HS 30, and HS 30 + MMPI were -26, -30, -23, and -31 mV, respectively. In conclusion, circulating TNF-alpha levels are affected by the rate of bleeding in hemorrhagic shock. However, despite the differences in the magnitude of TNF-alpha in untreated animals, hepatic integrity was compromised. Interestingly, MMPI, an inhibitor of TNF-alpha convertase, stabilizes the membrane potential in both types of hemorrhagic shock.