颈脊髓切断对内毒素血症大鼠急性肺损伤的影响

目的 研究颈脊髓切断对内毒素血症大鼠急性肺损伤的影响及可能机制.方法 72只SD大鼠随机分为3组:正常对照组(NC组,8只),内毒素血症组(ET组,32只)及内毒素血症+颈脊髓切断组(TCSC组,32只),后两组按不同时间点(3、6、12和48 h)又分为4个亚组,每个亚组8只.静脉注射脂多糖(LPS)10 mg/kg制备内毒素血症模型.TCSC组注射LPS前切断大鼠颈7脊髓.在不同时间点采血,并留取肺组织.采用高效液相色谱仪-电化学检测法和酶联免疫吸附法(ELISA)分别测定血浆去甲肾上腺素(NE)和白细胞介素-6(IL-6)的浓度;用血气分析仪检测动脉血氧分压(PaO2);观察各组大鼠肺组织病理学改变及肺湿/干重(W/D)比值.结果 TCSC组6、12和48 h血浆NE浓度、肺W/D比值较ET组均显著降低,PaO2较ET组显著升高,差异均有统计学意义(P均<0.05);TCSC组肺损伤程度减轻;3、6、12和48 h血浆IL-6均明显低于ET组(P均<0.05).相关性分析显示,血浆NE与IL-6浓度呈显著正相关(r=0.458,P<0.05),与PaO2呈显著负相关(r=0.528,P<0.05).结论 切断大鼠颈脊髓后造成去交感神经支配可能通过抑制肾上腺素能受体的过度激活而减轻内毒素血症大鼠急性肺损伤的程度,继而改善肺的氧合.     

地塞米松对内毒素休克大鼠脑组织细胞因子含量的影响

目的 探讨地塞米松对内毒素休克大鼠脑组织细胞因子含量的影响.方法54只健康成年Sprague-Dawley大鼠分为假手术组、脂多糖组和地塞米松组,后两组静脉注射脂多糖8 mg/kg,地塞米松组于造模成功后10 min静注地塞米松5 mg/kg.动态监测血压.分别于造模后lh、3h、6h用ELISA法检测脑组织中白细胞介素(IL)-4、IL-10和肿瘤坏死因子(TNF)-α的含量.结果 脂多糖组与假手术组比较,随着血压的下降,脑组织中IL-4、IL-10浓度减少(P＜0.01),TNF-α增加(P＜0.01);与脂多糖组比较,地塞米松组TNF-α含量减少(P＜0.01),IL-4、IL-10含量升高(P＜0.01).结论地塞米松能调节脂多糖诱导的内毒素休克大鼠脑内炎性因子,发挥脑保护作用.     

5-氟尿嘧啶对重症感染大鼠细胞因子的双相调节作用

目的 观察5-氟尿嘧啶(5-FU)对重症感染大鼠致炎细胞因子和抗炎细胞因子的调节作用,探讨5-FU对重症感染大鼠保护作用的机制.方法 将30只健康雌性Wistar大鼠随机分成正常对照组、重症感染组和5-FU治疗组,每组10只.重症感染组以无菌操作技术将大肠杆菌悬液(1.8×10"cfu/L)注入大鼠腹腔(10 ml/kg),制成重症感染模型;5-FU治疗组在重症感染模型制作成功后40 min再经腹腔注射5-FU(50 mg/kg).观察各组大鼠6 h死亡率和腹水率,然后处死大鼠,抽取下腔静脉血测定血浆中自细胞介素-6(IL-6)和IL-10的含量,称取肺组织湿重.结果 5-FU治疗组大鼠6 h死亡率和腹水率均低于重症感染组(P＜0.05和P＜0.01);重症感染组大鼠肺湿重较正常对照组增加(P＜0.01),5-FU治疗组大鼠肺湿重较重症感染组降低(P＜0.05),并恢复到正常水平.重症感染组血浆IL-6和IL-10水平明显升高(P均＜0.01);5-FU治疗组IL-6水平较重症感染组降低(P＜0.01),并恢复到正常水平,IL-10水平较重症感染组降低,但仍高于正常对照组(P均＜0.01).结论 5-FU可减少大鼠血浆致炎细胞因子和抗炎细胞因子的释放,减轻肺水肿,对重症感染具有保护作用.     

聚腺苷二磷酸核糖基聚合酶在大鼠失血性休克后血管低反应性发生中的作用

目的 研究聚腺苷二磷酸核糖基聚合酶(PARP)在大鼠失血性休克后血管低反应性发生中的作用.方法 将SD大鼠随机分为休克组、PARP抑制剂3-氨基苯甲酰胺(3-AB)预处理+休克组和假手术对照组,采用股动脉放血复制失血性休克模型.在体观察给予3 μg/kg去甲肾上腺素(NE)升高血压的幅度;离体测定肠系膜上动脉血管环对NE的反应性;硝酸还原酶法测定血浆和肠系膜上动脉血管环组织匀浆中一氧化氮(NO)的含量.结果 休克模型完成后即刻静脉给NE,休克组血压升高幅度显著低于假手术对照组(P＜0.01);回输血1 h后再次静脉给NE,休克组血压显著低于3-AB预处理+休克组和假手术对照组(P＜0.05和P＜0.01).假手术对照组最大收缩张力[(0.367 1±0.221 3)g/mm]＞3-AB预处理+休克组C(0.286 4±0.153 2)g/mm]＞休克组C(0.185 6±0.11 3)g/mm,P＜0.05或P＜0.01];与休克组比较,3-AB预处理+休克组量一效曲线左移,在NE终浓度为10-7、10-6和10-5 mol/L时其收缩力显著增加(P均＜0.05).3组间血浆NO含量差异均无统计学意义,3-AB预处理+休克组血浆和肠系膜上动脉组织匀浆中NO含量虽较休克组稍有降低,但两组问比较差异无统计学意义.结论 PARP参与了大鼠失血性休克后血管低反应性的发生.     

辛伐他汀对脓毒症早期大鼠肝脏损害的影响

目的探讨辛伐他汀对脂多糖(LPS)致大鼠脓毒症模型肝损害的保护作用及相关机制.方法将56只雄性 SD 大鼠按随机数字表法分为对照组(8只)、模型组(24只)、辛伐他汀组(24只).腹腔注射LPS 10 mg/kg 复制脓毒症大鼠模型.对照组和模型组于腹腔注射生理盐水或 LPS 前给予生理盐水1 ml/d 灌胃,辛伐他汀组于制模前给予辛伐他汀20 mg·kg-1·d-1灌胃,均连续1周.于制模后6、12、24 h 测定血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、肿瘤坏死因子-α(TNF-α)、白细胞介素(IL-6、IL-10)水平及肝脏组织丙二醛(MDA)含量,并观察24 h 肝脏组织病理学改变.结果与对照组比较,模型组和辛伐他汀组各时间点血清 ALT(U/L)、AST(U/L)、TNF-α(ng/L)、IL-6(ng/L)、IL-10(ng/L)及肝组织 MDA(nmol/mg)水平均明显升高(均P<0.05).模型组制模后12 h ALT、AST 达峰值,制模后6 h TNF-α、IL-6、IL-10、MDA 达峰值,以后有所下降.辛伐他汀组制模后24 h ALT、AST 较模型组下降更显著(ALT:60.5±8.9比81.8±13.9,AST:167.9±19.7比200.9±26.9,均 P<0.05),制模后6 h TNF-α较模型组显著降低(105.5±19.5比154.1±24.1,P<0.05),制模后6 h、12 h IL-6、MDA 较模型组明显下降(6 h IL-6:2910.9±353.6比3777.8±687.4,12 h IL-6:386.1±48.3比475.2±45.9;6 h MDA :0.60±0.09比0.73±0.12,12 h MDA :0.49±0.09比0.60±0.12,均P<0.05),IL-10较模型组显著升高(6 h:2090.6±262.5比1690.6±187.0,12 h:548.9±45.4比496.9±45.2,均P<0.05);24 h 肝组织病理学改变较模型组明显改善.结论辛伐他汀通过抗炎及减轻氧化应激反应对 LPS 诱导的脓毒症大鼠肝脏具有保护作用.     

抑制c-Jun蛋白氨基末端激酶信号通路对内毒素血症大鼠肠屏障功能的保护作用

目的 探讨阻断细胞质内应激信号通路c-Jun蛋白氨基末端激酶(JNK)对内毒素血症大鼠肠屏障损伤的保护作用.方法 24只雄性SD大鼠,按随机数字表法分为对照组、内毒素血症模型组、JNK抑制剂组3组,每组8只.对照组仅给予生理盐水2 ml/kg+JNK抑制剂SP600125的溶剂PPCES液2.5 ml/kg;内毒素血症模型组静脉注射脂多糖( LPS) 10 mg/kg+PPCES液2.5 ml/kg;JNK抑制剂组静脉注射LPS 10 mg/kg+JNK抑制剂SP600125 10 mg/kg.记录各组大鼠活动和生存情况;并于12h后取大鼠同肠,光镜下观察肠道黏膜病理改变;同时取血,采用酶联免疫吸附试验( ELISA)测定血浆D-乳酸含量.结果 对照组大鼠活动正常,无死亡;模型组大鼠精神萎靡、活动减少,12h内死亡1只;JNK抑制剂组大鼠活动较模型组活跃,无死亡.回肠黏膜病理检查显示:与对照组相比,模型组大鼠回肠组织黏膜水肿,绒毛缩短,炎性细胞浸润;INK抑制剂组回肠组织病变较模型组减轻.模型组大鼠血浆D-乳酸含量(μg/L)较对照组显著升高(943.8±439.6比227.9±130.0,P＜0.05);JNK抑制剂能显著降低内毒素血症大鼠血浆D-乳酸含量(637.4±114.4比943.8±439.6,P＜0.05).结论 抑制细胞质内应激信号通路JNK能减轻内毒素血症大鼠肠屏障损伤.     

不同剂量复方青黛颗粒对溃疡性结肠炎模型大鼠血清IL-6、IL-10水平的影响

目的 观察不同剂量复方青黛颗粒对溃疡性结肠炎(UC)模型大鼠血清白细胞介素-6(IL-6)、白细胞介素-10(IL-10)水平的影响.方法 将70只SD大鼠随机分为6组:空白对照组、模型对照组、柳氮磺胺吡啶(SASP)组、低剂量组(300 mg/ks)、中剂量组(600 mg/kg)及高剂量组(1 200 mg/kg).采用三硝基苯磺酸(TNBS)法制备UC大鼠模型,造模成功后各实验组分别给予SASP及不同剂量复方青黛颗粒灌胃,对照组给予等量生理盐水.连续给药10 d后观察各组大鼠给药后结肠组织病理学评分及血清IL-6、IL-10水平的差异.结果 空白对照组结肠组织病理学评分显著低于其他各组(P＜0.01),模型对照组显著高于其他各组(P＜0.05或P＜0.01),SASP组与高剂量组之间均有显著差异(P＜0.01),不同剂量组之间有显著差异(P＜0.05或P＜0.01).方差分析表明,空白对照组血清IL-6、IL-10水平与其他各组均有显著差异(P＜0.01),各给药组血清IL-6、IL-10水平均较模型对照组有不同程度改善,其中SASP组及高剂量组IL-6水平显著低于其他组(P＜0.05),高剂量组IL-10水平显著高于其他各组(P＜0.05).结论 复方青黛颗粒可有效改善UC模型大鼠的症状,降低IL.6的表达,并增加IL-10的表达,维持促炎性细胞因子与抗炎性细胞因子之间的平衡.     

骨髓间充质干细胞移植在光气吸入性肺损伤大鼠肺组织及血浆炎症因子的干预作用

目的：观察骨髓间充质干细胞（bone marrow derived mesenchymal stem cells, BMD-MSCs）移植对光气吸入性肺损伤大鼠肺组织及血浆炎症因子的干预作用。方法：96只雄性SD大鼠随机分为：空气对照组（A组）、BMD-MSCs干预对照组（AM组）、光气染毒组（PH组）、光气染毒后BMD-MSCs 干预组（PM组）,每组8只。染毒组按8.33 mg/L动态恒量染毒5 min。PM组染毒后即刻经尾静脉注射106 BMD-MSCs。4组分别于模型完成后6、24、48 h处死大鼠,取肺组织行病理检查及肺湿/干比、血气分析,取血浆行Bio-Plex细胞因子检测。结果：PH组较A组TNF-α浓度明显升高（P＜0.05）;PM组较PH组TNF-α浓度降低（P＜0.05）。PM组与PH组血浆IL-4浓度6 h、24 h均降低,以PM组下降更明显（P＜0.05）;48 h明显升高,以PM组升高更明显（P＜0.05）。PH组较A组IL-10浓度高（P＜0.05）;PM组较PH组IL-10浓度高（P=0.013）。结论：经尾静脉注射BMD-MSCs后可以使大鼠血浆中抗炎因子IL-4和IL-10逐渐升高,促炎因子TNF-α逐渐下降,提示其对光气致急性肺损伤大鼠肺具有保护作用。     

血管活性肠肽对内毒素性休克大鼠肺损伤的保护作用

目的 观察血管活性肠肽(VIP)对内毒索性休克大鼠肺损伤的作用,并探讨其可能机制.方法 SD大鼠静脉注射内毒素(E Coil LPS O111B4)10 mg/kg制作内毒素休克模型.随机将30只大鼠分成对照组(生理盐水,n=10)、内毒素组(内毒素10 mg/kg,n=10)和VIP组(内毒素10mg/kg+VIP 5 nmol,n=10).注药6 h后留取标本,测定各组肺干/湿比(W/D值)、支气管灌洗液(BALF)蛋白浓度和中性粒细胞计数,酶联免疫吸附法(ELISA)测定血清及BALF的肿瘤坏死因子-α(TNF-α)、白介紊-1(IL-1)和IL-10水平,观察肺组织病理变化(光镜+电镜).结果 内毒素组肺W/D值、BALF蛋白浓度和中性粒细胞计数比为(4.75±0.31),(68±6)%,(260±72)mg/L,对照组和VIP组分别为(3.61±0.28),(15±9)%,(70±21)mg/L和(4.02±0.25),(44±8)%,(123±44)mg/L,差异具有统计学意义(P＜0.05).内毒索组血清和BLAF中的TNF-α、IL-1β、IL-10明显升高(P＜0.05),VIP组与内毒素组比较TNF-α、IL-1β明显降低(P＜0.05),但仍高于对照组,IL-10较内毒素组进一步升高.光镜和电镜下VIP组病变轻于内毒素组.结论 VIP可减轻大鼠内毒索休克肺损伤,其作用机制可能与调控炎症细胞因子的表达有关.     

胆碱酯酶抑制剂中毒时血浆内毒素浓度变化的规律及宾赛克嗪的干预作用

目的 观察新型抗毒剂宾赛克嗪对维埃克斯染毒后不同时间点小鼠血浆内毒素浓度变化的影响及其机制.方法 306只雄性昆明小鼠被随机分为正常对照组、维埃克斯染毒模型组以及宾赛克嗪、阿托品和山莨菪碱3个治疗组;各治疗组分别于皮下注射维埃克斯0.02 mg/kg染毒前10 min经腹腔注射相应药物.各组均于染毒后1.5、3、6、24、48和72 h取血,检测血浆内毒素浓度.结果 与正常对照组[内毒素浓度为(1.90±0.41)kEU/L]比较,模型组1.5 h血浆内毒素浓度为(5.36±1.62)kEU/L,升高了约2倍;之后逐渐升高,至24 h达高峰,浓度为(11.47±3.90)kEU/L,较正常对照组升高了约5倍(P均<0.01),异常增高可持续至48 h,72 h后恢复至正常对照组水平.宾赛克嗪治疗组在1.5 h和3 h时内毒素浓度分别为(3.73±0.71)kEU/L和(3.95±1.26)kEU/L,显著低于模型组(p<0.01和P<0.05);6 h和24 h血浆内毒素浓度分别为(8.77±1.85)kEU/L和(11.47±2.51)kEU/L,与模型组比较差异无统计学意义,但显著高于正常对照组(P均<0.01);至48 h恢复至正常对照组水平.在相同实验条件下,阿托品治疗组血浆内毒素浓度在1.5～24 h显著高于模型组(P<0.05或P<0.01);而山莨菪碱治疗组血浆内毒素浓度在6 h达高峰,显著高于模型组(P<0.01).结论 维埃克斯染毒后1.5～48 h小鼠血浆内毒素浓度显著增高,使用宾赛克嗪能减轻胃肠道黏膜屏障功能的损伤,延缓内毒素进入血中的速度,并能缩短内毒素在血中的停留时间.而使用阿托品和山莨菪碱后则能加重胃肠道黏膜屏障功能的损伤.     

Effects of cervical chordotomy on systemic inflammatory response and the outcome in rats with endotoxic shock induced by lipopolysaccharide

OBJECTIVE: To investigate the effects of cervical chordotomy on systemic inflammatory response and the outcome in rats with endotoxemia induced by lipopolysaccharide (LPS). METHODS: Ninety-two Sprague Dawley (SD) rats were randomly divided into three groups: normal control group (groupI, n=8) , endotoxemia group (groupII, n=42) and endotoxemia with cervical chordotomy ( groupIII, n=42). Endotoxemia was induced by intra-peritoneal injection of LPS 10 mg/kg. In group III, "cervical chordotomy" was attained by transection of spinal cord at C7 immediately before intra-peritoneal LPS administration. Ten rats of groupII and III each were observed for 48-hour survival. The other rats were further divided into four subgroups of 8 animals each, according to the time when the animals were sacrificed . The animals were sacrificed at 3, 6, 12, and 48 hours after intra-peritoneal LPS injection. Heart blood samples were obtained for determination of plasma concentration of norepinephrine [NE, by high performance liquid chromatography (HPLC)] and plasma concentration of interleukin-10 (IL-10) and IL-6 [by enzyme linked immunosorbent assay (ELISA)]. RESULTS: Plasma NE concentration were significantly increased after intra-peritoneal LPS injection in groupIIand III as compared with group I and were significantly lower in group III than in groupII starting from 6 hours after LPS (all P<0.05). Plasma IL-10 concentration was significantly lower at 3 hours and 6 hours while plasma IL-6 concentration was significantly higher after LPS challenge in groupII than in groupIat all time points (all P<0.05). High transection of spinal cord significantly elevated plasma IL-10 level at 12 hours and 48 hours, lowered IL-6 release at 3, 6, and 12 hours (all P<0.05), and improved 48-hour survival (20% vs. 70%) in group III as compared with group II. CONCLUSION: Transection of spinal cord at C7 level can ameliorate the systemic inflammatory response induced by endotoxemia thus improving the outcome through elevation in IL-10 level, decreases in IL-6 release, and improves 48-hour survival. This might be attributable to loss of sympathetic nerve function.     

内毒素血症时循环肾素-血管紧张素系统改变的实验研究

目的研究大鼠内毒素血症时循环肾素-血管紧张素系统（RAS）的变化，探讨内毒素血症的病理机制。方法90只雄性Wistar大鼠，随机分为正常对照组（n=10）和模型组（n=80），模型组叉分为注射脂多糖（LPS）后2、4、8、12、24、48、72h及7d8个时间点。每个时间点10只。分别于腹腔注射LPS后相应时间点处死动物，取心脏血，测定血浆内毒素、肾素活性（PRA）、血管紧张素Ⅱ（AⅡ）以及血清肿瘤坏死因子-α（TNF-α）、白细胞介素-10（IL-10）、血管紧张素Ⅰ转换酶（ACE）的变化，并与正常对照组比较。结果①模型组血浆内毒素和血清TNF-α、IL-10水平均在腹腔注射LPS后2h达高峰，分别在注射LPS后7d、8h和8h降至正常水平。②模型组血浆PRA和血清AⅡ、ACE水平分别在腹腔注射LPS后2、8h和8h达高峰，分别于注射LPS后12、72和24h降至正常水平。结论内毒素血症时，机体产生一系列炎症反应和抗炎反应，释放大量细胞因子和炎症介质，同时循环RAS激活，引起血管收缩，导致微循环障碍．可进一步加重组织细胞缺血、缺氧。研究内毒素血症时RAS改变对阐明内毒素血症的病理机制具有一定价值。     

血管紧张素Ⅱ在急性肺损伤大鼠循环及肺组织中的表达

目的 研究大鼠急性肺损伤时循环及肺组织血管紧张素Ⅱ(AngⅡ)含量的变化,探讨AngⅡ在急性肺损伤发病中的作用.方法 清洁级SD大鼠30只,随机分为正常对照组(n=6)和模型组(n=24),模型组又按注射脂多糖(LPS)后3、6、9、12 h四个时间点分成4组,每组6只.分别于静脉注射LPS后各分组时间点观察大鼠一般情况、血压、动脉血气分析、肺组织湿质量/干质量(W/D)比值、肺组织病理改变,放免法测定血浆及肺组织AngⅡ的含量的变化,所有观察指标采用单因素方差分析与正常对照组比较.结果 与正常对照组比较,pH值和动脉血氧分压显著降低(P＜0.05),而二氧化碳分压及肺W/D比值均显著高于对照组(P＜0.05),病理形态学积分分析显示肺组织受损(P＜0.01).ALI大鼠血浆及肺组织AngⅡ均升高(P＜0.05),其中血浆AngⅡ在9 h时点达峰值,而组织Ang Ⅱ浓度在各观察时间点持续上升.结论 ALI时肺组织和血中Ang Ⅱ大量释放,提示ALI时伴有全身及肺局部肾素-血管紧张素系统的激活.     

腹腔复苏对失血性休克大鼠肺损伤的保护作用

目的探讨腹腔复苏对失血性休克大鼠肺损伤的保护作用。方法健康雄性SD大鼠40只,随机分成假手术组(Ⅰ组)、失血性休克组(Ⅱ组)、静脉复苏组(Ⅲ组)、PD-2液腹腔复苏加静脉复苏组(Ⅳ组)。Ⅰ组依次行右颈总动脉、右股静脉、左股动脉插管及全身肝素化;Ⅱ组在Ⅰ组基础上制备失血性休克大鼠模型;Ⅲ组在Ⅱ组基础上于造模后经右股静脉补入放出的血量及2倍量林格氏液进行静脉复苏;Ⅳ组在Ⅲ组基础上同时腹腔内注入30 mL2.5%PD-2液。各组分别于T0、T1、T2进行PaO2/FiO2值血气分析;T2时测定肺组织W/D比值,TNF-α、IL-1β、IL-10的含量,观察肺组织病理学结果。结果与Ⅰ组比较,Ⅱ组PaO2/FiO2值明显降低,Ⅲ组于T0、T2时下降明显,Ⅳ组T0时下降明显;与Ⅰ组比较,Ⅱ组、Ⅲ组、Ⅳ组肺组织TNF-α、IL-1β、IL-10的含量和W/D比值均升高(P<0.01),与Ⅱ组比较,Ⅲ组和Ⅳ组降低,Ⅳ组肺组织IL-10含量升高(P<0.05或P<0.01)。与Ⅳ组比较Ⅲ组肺组织IL-10含量降低;肺组织病理学比较,Ⅱ组较Ⅰ组有明显损伤,Ⅳ组病理损伤最轻。结论 PD-2液腹腔复苏能够减轻失血性休克大鼠肺组织损害的程度,降低炎症反应,对肺损伤具有保护作用。     

脓毒症大鼠有核细胞过氧化物酶体增殖物激活受体γ活性与白细胞介素-6的关系

目的 观察脓毒症时有核细胞过氧化物酶体增殖物激活受体γ(PPAR7)活性、血浆促炎介质白细胞介索-6(IL-6)的变化,探讨两者的关系.方法 按随机数字表法将90只SD大鼠分为正常对照组、假手术组、脓毒症组,每组再分为术后12、24、48 h 3个亚组,每组10只.采用盲肠结扎穿孔术(CLP)制作大鼠脓毒症模型,用酶联免疫吸附法(ELISA)测定有核细胞PPAR7活性及血浆IL-6水平.结果 脓毒症组术后12、24、48 h有核细胞PPART活性(A值:0.279±60.004、0.264±0.009、0.245±0.012)较正常对照组(0.292±0.007、0.293±0.004、0.293±0.005)和假手术组(0.295±0.008、0.295±0.006、0.294±0.007)明显下降,而血浆IL-6水平(ng/L:365.25±15.53、507.16±20.86、437.89±25.09)较正常对照组(43.54±11.10、48.82±10.62、42.96±9.52)和假手术组(42.43±6.77、40.32±6.48、44.10±9.36)明显升高(均P＜0.05);且脓毒症组随病情加重PPARγ活性逐渐下降,IL-6于24 h达高峰后下降,组内各时间点间两两比较差异均有统计学意义(均P＜0.05).脓毒症大鼠12 h时有核细胞PPARγ活性与血浆IL-6水平呈显著负相关(r=-0.703,P=0.023).结论 脓毒症有核细胞PPARγ活性下降,血浆促炎介质IL-6升高,且两者呈负相关.

Abstract：

Objective To observe the relationship between activity of peroxisome proliferator activated receptor γ (PPARγ) in nucleated cell and level of pro-inflammatory mediator interleukin-6 (IL-6) in plasma of rats with sepsis. Methods According to the random number table, 90 male Sprague-Dawley (SD)rats were randomly divided into three groups, namely control group, sham operation group and sepsis group.Each group was further divided into three subgroups according to postoperative time points, i.e. 12, 24 and 48-hour subgroups. Each subgroup consisted of 10 rats. Sepsis was reproduced by cecal ligation and puncture (CLP). The PPARγ activity in nucleated cells and IL-6 level in plasma were detected by enzyme-linked immunosorbent assay (ELISA). Results The PPARγ activity in nucleated cells was significantly decreased at 12, 24 and 48 hours in sepsis group (A value: 0. 279±0. 004, 0. 264±0. 009, 0. 245±0. 012) compared with control group (0. 292 ± 0. 007, 0.293 ±0.004, 0.293 ±0.005) and sham operation group (0. 295 ±0.008, 0.295 ±0.006, 0. 294 ± 0. 007), while the IL-6 level was significantly increased in sepsis group (ng/L; 365. 25 ±15. 53, 507.16 ±20. 86, 437. 89 ±25.09) compared with control group (43. 54 ± 11.10,48. 82±10. 62, 42. 96±9. 52) and sham operation group (42. 43±6. 77, 40. 32±6. 48, 44.10±9. 36, all P＜0. 05). When septic condition became worse, the PPARγ activity in nucleated cells of sepsis group lowered,and IL-6 level was gradually elevated after operation, reaching the peak at 24 hours, and then gradually lowered, and the difference of the value between any two time points was all statistically significant (all P＜0. 05). There was a negative correlation between the PPARγ activity in nucleated cells and IL-6 level in 12-hour subgroup of sepsis group (r=-0. 703, P=0. 023). Conclusion In septic rats, the PPARγ activity in nucleated cells was lowered while the pro-inflammatory mediator IL-6 level in plasma elevated, and there was a negative correlation between PPARγ activity and IL-6 level.     

血管紧张素-Ⅱ活化肺微血管内皮细胞核因子-κB的研究

目的 探讨血管紧张素Ⅱ(Ang Ⅱ)对肺微血管内皮细胞(HPMEC)核因子-κB(NF-κB)的活性的影响,以及经典途径在Ang Ⅱ介导的NF-κB活化过程中的作用.方法 本实验分为:Ang Ⅱ组:10-6 mol/L AngⅡ分别刺激HPMEC 0、0.5、1、2、4 h;氯沙坦组:10-6mol/L氯沙坦(AngⅡ 1型受体阻滞剂)预先处理HPMEC 1 h,再予相同10-6mol/L AngⅡ刺激细胞2 h,提取胞浆蛋白和胞核蛋白.凝胶电泳迁移率分析实验(EMSA)观察细胞中NF-κB的DNA结合活性.Western印迹检测细胞浆中抑制因子κBα(IκBα)的含量.结果 AngⅡ刺激HPMEC 0.5 h后细胞中NF-κB活性明显上升(144.5±16.1),在2h达到峰值(270.1±27.2),4 h(215.1±17.8)较2 h有所下降,但仍高于0 h水平,以上各时间点与AngⅡ刺激细胞0 h(100.0±25.1)相比,差异有统计学意义(P＜0.05).与Ang Ⅱ刺激HPMEC 0 h IκBα含量(44.4%±2.1%)相比,0.5 h后IκBα含量即开始明显下降(38.9%±3.6%,P＜0.05),2 h后IκBα含量下降最为明显(32.6%±2.3%,P＜0.05),4 h细胞中IκBα含量较2 h有所上升,但仍然明显低于ArgⅡ刺激0 h细胞中IκBα的含量(40.1%±4.7%,P＜0.05).氯沙坦组NF-κB活性(115.4±10.7)和IκBα含量(43.6%±3.7%)与AngⅡ组0 h相比无明显差异.氯沙坦组中NF-κB活性明显低于AngⅡ组2 h,氯沙坦组中iκBα的含量亦明显高于AngⅡ组2 h.结论 AugⅡ能通过AT1介导HPMEC中NF-κB活化.经典途径参与了AagⅡ诱导的HPMEC中NF-κB活化过程.     

Effects of partial liquid ventilation on lipopolysaccharide-induced inflammatory responses in rats

To determine whether partial liquid ventilation (PLV) modified lung inflammatory response, we analyzed blood cytokine levels and cytokine mRNA expression in the lungs, using a rat model of endotoxemia. Thirty-six rats were allocated into one of four groups. The first group received conventional gas ventilation (CV group), the second group received 10 ml/kg perflubron intratracheally in combination with mechanical gas ventilation (PLV group), the third group received 20 mg/kg Escherichia coli lipopolyssacharide (LPS) intravenously in combination with mechanical gas ventilation (LPS group), and the fourth group received PLV and LPS (PLV + LPS group). Blood levels of TNF-alpha, IL-1beta, IL-6, IL-10, INF-gamma and IL-1 receptor antagonist were significantly increased in LPS and PLV + LPS groups. mRNA expression of pro- and anti-inflammatory cytokines in the lung tissue was also significantly increased in these groups. mRNA expression of IL-6 in PLV + LPS group was significantly increased in comparison with LPS group. Other cytokine mRNA expression including IL-10 and IL-1beta was also potentiated in PLV + LPS group, however this was not significant. Our results suggest that PLV does not protect the lungs against inflammation in systemic endotoxemia in rats.     

亚低温对急性肺损伤大鼠肺泡表面活性蛋白A含量的影响

目的 探讨亚低温对内毒素脂多糖(LPS)诱导急性肺损伤(ALI)大鼠肺泡表面活性蛋白A(SP-A)含量的影响.方法 按随机数字表法将40只雄性Wistar大鼠分组.采用气管内滴入LPS制备ALI动物模型;对照组气管内只滴人生理盐水.模型组和对照组分别于术后1 h和8 h处死8只大鼠;亚低温组于滴入LPS 1 h后将体温降低并维持在32.5～33.0℃,8 h后处死8只大鼠.各组分别于术前及术后1 h、8 h测定动脉血气,并计算氧合指数(PaO2/FiO2);采用酶联免疫吸附法检测支气管肺泡灌洗液(BALF)中SP-A含量;光镜下观察肺组织形态结构的变化.结果 气管内滴入LPS 1 h后,大鼠PaO2/FiO2均达到ALI的诊断标准.与对照1 h组比较,模型1 h组BALF中SP-A含量(μg/L)明显降低(53.27±1.95比74.81±6.55,P＜0.01);模型8 h组和亚低温8 h组SP-A含量(4.35±2.76和51.36±2.33)均较对照8 h组(70.81±5.01)明显降低,但亚低温8 h组SP-A含量较模型8 h组明显增高(均P＜0.01).光镜下观察,对照1 h和8 h组肺泡结构基本正常;模型8 h组肺组织炎症反应最重;模型1 h组和亚低温8 h组肺组织炎症反应较模型8 h组有所减轻.结论 亚低温能延缓内毒素诱导的ALI大鼠早期肺泡内SP-A含量下降的程度,在一定程度上可减轻肺损伤.

Abstract：

Objective To investigate the effect of hypothermia (HT) on the concentration of surfactant protein A (SP-A) during lipopolysaccharide (LPS) induced acute lung injury (ALI) in rats.Methods Forty male Wistar rats were randomly divided into three groups. The ALI model was reproduced by LPS intratracheal instillation; only saline was instilled intratracheally for control group. Rats in both model group and control group were sacrificed respectively at 1 hour and 8 hours (each n= 8). In HT group the body temperature was lowered to 32. 5 - 33.0 ℃ 1 hour after LPS instillation, and 8 rats were sacrificed st 8 hours. The arterial blood gas was determined in all the groups before and 1 hour and 8 hours after instillation of saline or LPS, and the oxygenation index (PaO2/FiO2) was calculated. The concentration of SP-A in bronchoalveolar lavage fluid (BALF) was determined by enzyme linked immunosorbent assay. The morphological changes in lung tissue of rats were observed under light microscope. Results At 1 hour after intratracheal instillation of LPS, the PaO2/FiO2 of each group reached the diagnostic criterion of ALI.Compared with control 1-hour group, the SP-A (μg/L) in BALF of model 1-hour group was decreased (53. 27±1.95 vs. 74. 81±6. 55, P＜0. 01); the SP-A in model 8-hour group and HT 8-hour group (4.35±2. 76 and 51.36±2. 33) was both obviously decreased compared with control 8-hour group (70. 81±-5. 01,both P＜0. 01). Compared with model 8-hour group, the SP-A of HT 8-hour group was obviously increased (P＜0. 01). Results of light microscopic examination, it was revealed that the alveolar structure of control 1-hour group and control 8-hour group was almost normal. Inflammatory response in lung tissues in model 8-hour group was found to be most serious; compared with model 8-hour group, inflammatory response in lung tissues in model 1-hour group and HT 8-hour group was reduced in certain degree. Conclusion A certain extent of HT may reduce lung injury of early endotoxin-induced ALI rats by delaying lowering of alveolar SP-A levels.