血红素加氧酶1对模拟移植后犬肺功能的影响

背景:血红素加氧酶1是机体调节和抵抗氧化应激反应的重要生物分子,参与器官移植、缺血再灌注损伤等过程.目的:应用犬离体肺移植再灌注模型模拟肺移植后的循环过程,观察预先诱导犬肺血红素加氧酶1过表达对模拟移植犬肺功能的影响.设计、时间及地点:随机对照动物实验,于2005-12/2006-03在解放军空军总医院实验动物中心完成.材料:健康杂种犬12只用于制备犬离体肺移植再灌注模型.方法:按随机数字表法分3组(n=4):模型组即单纯肺缺血再灌注组;诱导剂组和抑制剂组预先给予血红素加氧酶l诱导剂氯化血红素,抑制剂组于再灌注时向灌注液中加入血红素加氧酶1抑制剂锌原卟啉.主要观察指标:比较分析各组犬肺组织中血红素加氧酶1 mRNA的表达水平.以及模拟移植后血气指标、肺动脉压、肺组织丙二醛含量和超氧化物歧化酶活性.结果:12只犬全部进入结果分析.①诱导剂组血红素加氧酶1 mRNA表达水平高于模型组和抑制剂组(P＜0.01).②模拟移植后各组肺动脉压均呈先增高后降低的趋势.模拟移植后30 min左右肺动脉压达高峰.③模拟移植后120 min,诱导剂组动脉血氧分压高于模型组和抑制剂组(P＜0.05),动脉血二氧化碳分压低于模型组和抑制剂组(P＜0.05):模型组与抑制剂组以上指标差异均无显著性意义(P＞0.05).④模拟移植后120min.各组丙二醛含量均升高,诱导剂组低于模型组和抑制剂组(P＜0.05):各组超氧化物歧化酶活性均下降,诱导剂组高于模型组和抑制剂组(P＜0.05).结论:过表达血红素加氧酶1能明显改善模拟移植的犬肺功能.     

正铁血红素改善链脲佐菌素诱导的糖尿病大鼠肝损伤

目的 探讨血红素加氧酶1(HO-1)诱导剂正铁血红素和抑制剂锌原卟啉对糖尿病大鼠肝功能的影响及相关机制.方法 以链脲佐菌素腹腔注射诱导糖尿病SD大鼠模型,大鼠分为对照组、糖尿病组、正铁血红素组和锌原卟啉组.应用试剂盒检测各组大鼠血清游离脂肪酸(FFA)、丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)活性,肝组织匀浆总抗氧化能力(TAOC)和丙二醛(MDA);逆转录-聚合酶链反应(RT-PCR)法检测肝脏组织白细胞介素1(IL-1)和肿瘤坏死因子α(TNF-α)mRNA表达水平.结果 与对照组比较,糖尿病组大鼠血清AST、ALT、肝组织MDA、IL-1、TNF-α mRNA水平均明显增高(P＜0.01或＜0.05),分别是(91.59±12.38) U/L vs (50.19±12.65)U/L、(45.64±9.68) U/L vs (15.55±7.79) U/L,(0.81±0.22) nmol/mg vs (0.50±0.08) nmol/mg、12.32±3.51vs 7.02±1.99、22.24±4.48 vs 10.54±2.36;TAOC下降(P＜0.05);与糖尿病组大鼠比较,正铁血红素组大鼠ALT、TNF-α表达水平明显下降,TAOC增高(P＜0.05或＜0.01);锌原卟啉组大鼠较糖尿病组大鼠FFA、ALT、AST、MDA均有明显上升(P＜0.05或＜0.01),而TAOC下降(P＜0.05).结论 HO-1诱导剂正铁血红素可改善糖尿病大鼠肝损伤,而其抑制剂则加重肝脏损伤.     

迟发缺血预处理低温保存肾移植供体中血红素加氧酶1的表达

背景:缺血预适应延迟反应通过诱导保护性蛋白增强组织对缺血再灌注损伤的耐受能力;血红素加氧酶1参与缺血预适应延迟保护作用。迟发缺血预处理对低温保存肾脏的作用及血红素加氧酶1是否参与其中尚不清楚。目的:观察缺血预处理诱导血红素加氧酶1的迟发缺血预处理反应对低温保存肾脏移植供体的作用。方法:雄性SD大鼠随机分入5组:空白对照组、低温保存组、缺血预处理组、缺血+低温组(n=12);缺血+给药+低温组。各组大鼠均行右肾切除,预处理或假手术操作处理后24h采用大鼠肾脏非循环离体灌注模型获取肾脏,分别于保存24,48,72h取样。缺血+给药+低温组除上述处理外,还于原位低温灌注术前1h接受1次血红素加氧化酶1抑制剂锡原卟啉腹腔注射。低温保存肾脏于各保存终点留取保存液,测定pH值和乳酸脱氢酶含量;切取1/2肾脏按照光镜要求制备标本送检;剩余1/2肾脏用于免疫印迹法测定血红素加氧酶1表达,比色法测定皮质Na-K-ATP酶活性、丙二醛和还原型谷胱甘肽含量;未保存肾脏仅通过免疫印迹法测定血红素加氧酶1的基础表达情况。结果与结论:迟发缺血预处理诱导了肾组织血红素加氧酶1的表达,与单纯低温保存组相比保存24,48h后,缺血+低温组保存液pH值、乳酸脱氢酶活性降低;肾脏组织Na-K-ATP酶活性、谷胱甘肽含量增加,丙二醛含量降低;同时点预处理组肾组织光镜形态学改变稍好于单纯低温保存组。给予血红素加氧酶1抑制剂后,这种保护作用消失。提示,迟发缺血预处理延长了肾脏低温保存时限,这可能与诱导血红素加氧酶1,增加组织抗氧化能力,减轻低温保存氧应激有关。     

血红素氧合酶-1保护心力衰竭大鼠肠道结构屏障

目的研究血红素氧合酶-1(HO-1)对心力衰竭大鼠肠道结构屏障的保护作用及其作用途径。方法通过冠状动脉结扎术造成心肌梗死建立心力衰竭大鼠模型(雄性,Wistar大鼠),分为MI+Copp(钴-原卟啉)组、MI(心肌梗死)模型组、MI+SnMP(锡中卟啉)组,相同数量(n=10)正常大鼠作为对照组(Control),分别腹腔注射Copp溶液、生理盐水、SnMP溶液、生理盐水。8周后在无菌术操作下取材肝、脾、肠系膜淋巴结,并匀浆细菌培养,计算细菌移位率;取小肠做HE染色观察病理。通过实时定量荧光PCR(Real-time PCR)测定小肠血红素氧合酶-1 RNA的表达,比色法测定小肠一氧化碳(CO)水平。结果同MI比较,MI+Copp明显升高小肠血红素氧合酶-1 RNA表达(P<0.01)及CO浓度(P<0.05),减轻小肠病理改变(P<0.05),并减少细菌移位率(P<0.01)、血浆内毒素含量[门静脉(61.790±21.038)pg/ml,下腔静脉(49.310±25.273)pg/ml,P<0.05]。而MI+SnMP对血红素氧合酶-1 RNA表达无明显影响(P>0.05),但明显降低小肠CO浓度(P<0.05),加重小肠病理改变(P<0.01),并升高细菌移位率(P<0.05)、血浆内毒素含量[门静脉(165.016±40.751)pg/ml,下腔静脉(141.249±40.772)pg/ml,P<0.01]。结论血红素氧合酶-1可明显减少心力衰竭大鼠细菌移位率及血浆内毒素含量,该作用可能与CO保护肠道屏障结构有关。     

血红素加氧酶-1对心肌缺血再灌注损伤的保护作用

目的:探讨血红素加氧酶-1(HO-1)对心肌缺血再灌注损伤的保护作用及机制。方法:采用HO-1的诱导剂钴原卟啉(CoPP)和抑制剂锌原卟啉(ZnPP)分别进行干预处理后,建立大鼠的心肌缺血/再灌注损伤模型。观察大鼠再灌注后心肌形态变化,检测HO-1基因在大鼠心肌的表达情况,测定大鼠左心室心肌组织超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量。结果:再灌注前使用CoPP进行预处理,可以诱导HO-1蛋白的表达上调;HO-1蛋白表达上调可以减少缺血再灌注后的心肌细胞坏死,提高心肌组织中SOD含量并降低MDA的含量。结论:CoPP诱导的HO-1过表达可以抑制心肌缺血再灌注损伤后的细胞坏死,从而减轻心肌的再灌注损伤,其主要机制与抗氧自由基有关。     

迟发缺血预处理低温保存肾移植供体中血红素加氧酶1的表达

背景：缺血预适应延迟反应通过诱导保护性蛋白增强组织对缺血再灌注损伤的耐受能力;血红素加氧酶1参与缺血预适应延迟保护作用。迟发缺血预处理对低温保存肾脏的作用及血红素加氧酶1是否参与其中尚不清楚。目的：观察缺血预处理诱导血红素加氧酶1的迟发缺血预处理反应对低温保存肾脏移植供体的作用。方法：雄性SD大鼠随机分入5组：空白对照组、低温保存组、缺血预处理组、缺血＋低温组（n=12）;缺血＋给药＋低温组。各组大鼠均行右肾切除,预处理或假手术操作处理后24h采用大鼠肾脏非循环离体灌注模型获取肾脏,分别于保存24,48,72h取样。缺血＋给药＋低温组除上述处理外,还于原位低温灌注术前1h接受1次血红素加氧化酶1抑制剂锡原卟啉腹腔注射。低温保存肾脏于各保存终点留取保存液,测定pH值和乳酸脱氢酶含量;切取1/2肾脏按照光镜要求制备标本送检;剩余1/2肾脏用于免疫印迹法测定血红素加氧酶1表达,比色法测定皮质Na-K-ATP酶活性、丙二醛和还原型谷胱甘肽含量;未保存肾脏仅通过免疫印迹法测定血红素加氧酶1的基础表达情况。结果与结论：迟发缺血预处理诱导了肾组织血红素加氧酶1的表达,与单纯低温保存组相比保存24,48h后,缺血＋低温组保存液pH值、乳酸脱氢酶活性降低;肾脏组织Na-K-ATP酶活性、谷胱甘肽含量增加,丙二醛含量降低;同时点预处理组肾组织光镜形态学改变稍好于单纯低温保存组。给予血红素加氧酶1抑制剂后,这种保护作用消失。提示,迟发缺血预处理延长了肾脏低温保存时限,这可能与诱导血红素加氧酶1,增加组织抗氧化能力,减轻低温保存氧应激有关。     

1型糖尿病大鼠血管内皮细胞损伤后血生化学指标变化及锌原卟啉、正铁血红素的干预效应

目的:观察1型糖尿病血管内皮细胞损伤后内源性一氧化碳、血清总抗氧化能力、丙二醛、游离脂肪酸水平变化,以及锌原卟啉、正铁血红素对这种变化的干预结果。方法:实验于2004-10/2005-06在河北省人民医院老年医学省重点实验室完成。①选用健康雄性SD大鼠89只,8周龄,体质量240～260g。②取17只为对照组:腹腔仅注射柠檬酸缓冲液,4d后隔日腹腔注射生理盐水。将其余72只造成1型糖尿病模型:大鼠按50mg/kg一次性腹腔注射链脲佐菌素(溶于pH4.5的柠檬酸缓冲液中),4d后,有60只大鼠空腹血糖>16mmol/L为1型糖尿病模型复制成功。将其随机分为3组:1型糖尿病组(n=36):造模4d后隔日腹腔注射生理盐水,饲养4,8和12周后处死12,14,10只;正铁血红素 1型糖尿病组(n=12):造模4d后隔日给1型糖尿病大鼠腹腔注射正铁血红素30μmol/kg,连续4周后处死;锌原卟啉 1型糖尿病组(n=12):造模4d后隔日给1型糖尿病大鼠腹腔注射锌原卟啉10μmol/kg,连续4周后处死。③处死前采用Chrion855血气分析仪检测动脉血中碳氧血红蛋白水平,以其反映一氧化碳水平。采用比色法检测血清总抗氧化能力,丙二醛和游离脂肪酸水平。扫描电镜观察股动脉内皮超微结构。④多组均数比较采用单因素方差分析,组间比较采用LSD法。结果:由于造模失败脱失12只,最终进入结果分析77只。①动脉血碳氧血红蛋白水平:1型糖尿病大鼠4周明显低于对照组(P<0.01),正铁血红素 1糖尿病组干预4周后明显高于1型糖尿病组干预4周后(P<0.05),干预8,12周后低于对照组,但差异不明显。②血清总抗氧化能力水平:1型糖尿病大鼠呈时间依赖性降低,均明显低于对照组(P<0.01),锌原卟啉 1型糖尿病组干预4周后明显低于1型糖尿病组干预4周后(P<0.05)。③血清丙二醛水平:1型糖尿病大鼠呈时间依赖性升高,其中干预8,12周后明显高于对照组(P<0.01),锌原卟啉 1型糖尿病组干预4周后明显高于1型糖尿病组干预4周后(P<0.05)。④血清游离脂肪酸水平:锌原卟啉 1型糖尿病组干预4周后明显高于1型糖尿病组干预4周后(P<0.05),1型糖尿病组干预12周后明显高于干预4周后(P<0.05)。⑤股动脉内皮超微形态学观察结果:对照组内皮细胞形态结构正常。1型糖尿病组内皮细胞出现损伤,干预8,12周后可见内皮细胞更严重损伤;应用正铁血红素后1型糖尿病大鼠内皮细胞形态接近对照组;锌原卟啉 1型糖尿病组大鼠内皮细胞形态异常。结论:随病程进展1型糖尿病大鼠内皮细胞抗氧化能力逐渐降低,脂代谢紊乱更加严重,内源性一氧化碳水平下降,并逐渐接近正常。锌原卟啉可加重血管内皮细胞结构损伤,应用正铁血红素可减轻血管内皮细胞结构损伤。     

辛伐他汀对实验性兔动脉粥样硬化进程中HO/CO系统的影响

目的探讨血红素加氧酶(HO)一氧化碳(CO)系统在动脉粥样硬化中的变化、相互关系及辛伐他汀对动脉粥样硬化进程中血红素加氧酶-一氧化碳的影响。方法家兔予以高胆固醇饮食(n=16)8周,8周后改用普通饮食并随机分为3组,模型组停用高胆固醇饮食,改普通饮食(n=8);辛伐他汀组给予喂饲辛伐他汀进行药物干预8周。同时设正常对照组(n=8):给予普通饲料喂养16周。然后取静脉血分别用Chalmers A.H、硝酸还原酶法测定各实验组血中CO,取主动脉组织用免疫组织化学方法测定主动脉组织中HO-1的表达;并比较组间各项参数的差异。结果与对照组比较,模型组血脂水平明显升高,血浆一氧化碳水平明显升高,血红素加氧酶-1表达明显升高(P均<0.01)。与模型组比较辛伐他汀组血浆TC、TG、LDL下降明显(P<0.01),HDL升高(P<0.01);血浆一氧化碳水平明显降低(P<0.01),血红素加氧酶-1表达明显减少(P<0.01)。结论动脉粥样硬化进程中,辛伐他汀可以通过下调血红素加氧酶/一氧化碳系统而延缓动脉粥样硬化进程。     

血红素加氧酶-1对糖尿病大鼠神经病理性疼痛的影响及可能的机制

目的:通过抑制和诱导血红素加氧酶-1(HO-1)的表达,探讨其对糖尿病大鼠神经病理性疼痛的影响及可能的机制。方法:将造模成功的24只糖尿病大鼠随机分为3组(n=8):糖尿病组(A组);糖尿病+锌原卟啉干预组(B组);糖尿病+钴原卟啉干预组(C组)。另取8只大鼠作为正常对照(D组)。于造模前及造模后不同时点测大鼠的机械性缩足反应阈值(paw withdrawalmechanical threshold,PWMT)。造模后43 d麻醉大鼠,取坐骨神经制成电镜标本;取L4~L6段脊髓,行HE染色、免疫组化染色及原位末端标记(TUNEL)检测。结果:与造模前相比,A、B、C组造模后7~42 d的PWMT显著降低(P<0.01)。造模后14~42 d,与A组比,C组PWMT显著升高(P<0.05),而B组则显著降低(P<0.05)。C组脊髓背角神经元及坐骨神经病变的程度较A组减轻;而B组则较A组加重。与A组比,C组脊髓背角神经元胞浆中HO-1表达增强,凋亡发生率显著降低(P<0.01);而B组HO-1表达减弱,凋亡发生率显著升高(P<0.01)。结论:HO-1对糖尿病神经病理性疼痛有治疗作用,这可能与其能够减轻糖尿病外周神经病变及抑制脊髓背角神经元凋亡有关。     

吲哚胺2,3-二氧化酶转染供体可抑制大鼠肝移植的急性排斥反应

背景:吲哚胺2,3-二氧化酶(indoleamine2,3-dioxygenase,IDO)表达于免疫特赦器官中,能选择性诱导T细胞免疫耐受。目的:观察腺病毒相关质粒载体介导IDO转染供体对大鼠肝移植急性排斥反应的抑制作用。方法:构建携带IDO的重组腺病毒质粒pWCM-IDO,建立PVG/DA大鼠肝移植模型48对,随机分为3组,生理盐水组、pWAV2组、pWCM-IDO组分别腹腔注射生理盐水、pWCM悬液和pWCM-IDO悬液1mL。结果与结论:pWCM-IDO可成功转染PVG供体肝脏,PWCM-IDO组生存期和IDO表达明显高于生理盐水组和pWAV2组(P<0.05~0.01);移植后第4天PWCM-IDO组急性排反应程度明显弱于其他2组。提示IDO的重组腺病毒质粒可成功转染大鼠肝脏,缓解急性排斥反应,但难以持续有效表达,对免疫排斥的抑制作用有限。     

血红素氧合酶对复苏后心功能不全的保护作用

目的 探讨诱导血红素氧合酶表达对复苏后心肌损伤的保护作用,为复苏后心功能不全探索新的治疗手段.方法 采用窒息法制作大鼠心跳骤停与心肺复苏(CPR)模型.实验动物分为4组:假手术组、CPR组、血晶素组(Hemin组)、血晶素+锌原卟啉组(Hemin+ZnPP组),各复苏组又分复苏后6 h及24 h 2个亚组.各实验组记录血流动力学资料;测定血清肌酸肌酶同功酶(CPK-MB)、乳酸脱氢酶(LDH)含量;测定心肌组织匀浆HO-1含量;观察心肌超微结构变化.对结果进行方差分析.结果 各复苏组复苏后平均动脉压(MBP)显著低于复苏前(均P＜0.05),但组间比较差异无统计学意义.CPR组、Hemin+ZnPP组复苏后各时相点dp/dt40值、-dp/dt值均显著低于复苏前(P＜0.05),但Hemin组复苏前后dp/dt40值无显著性变化,-dp/dt值仅复苏后0.5 h和1 h低于复苏前(P＜0.05);Hemin组复苏后各时相点dp/dt40值、-dp/dt值均高于其他两组(P＜0.05).复苏后6h及24 h血清CPK-MB、LDH水平,Hemin组均低于CPR组及Heroin+ZnPP组(P＜0.05),但CPR组和Hemin+ZnPP组两组之间比较差异无统计学意义.Hemin组复苏后6 h心肌超微结构完整性明显优于CPR组及Hemin+ZnPP组.复苏后6 h及24 h心肌组织匀浆HO-1水平,Hemin组均高于CPR组及Hemin+ZnPP组(均P＜0.05),但CPR组和Hemin+ZnPP组两组之间差异无统计学意义(P＞0.05).结论 诱导HO-1表达可有效改善复苏后心功能不全,减轻心肌损伤,保存心肌细胞超微结构的完整性,为复苏后心功能不全的治疗提供了新的手段.     

丹参对大鼠移植肝血红素氧合酶1表达的影响

背景：器官移植前使用丹参预处理能够保护组织缺血-再灌注损伤,改善移植器官存活率。目的：观察含丹参的冷灌注液对同种异体大鼠移植肝脏中血红素氧合酶1表达的影响,以及对供体肝脏缺血-再灌注损伤的保护作用。方法：将SD雄性大鼠随机分成UW液组（术中使用UW液灌注保存）、丹参＋UW液组（术中使用丹参＋UW液灌注保存）、ZnPP预处理组（移植前24h腹腔内注射ZnPP,术中使用丹参＋UW液灌注保存）,建立稳定的大鼠同种异体肝移植模型。同时取10只正常大鼠作为正常对照。结果与结论：丹参＋UW液组和UW液组血清总胆红素、谷丙转氨酶、谷草转氨酶水平明显低于ZnPP预处理组（P〈0.01）。血红素氧合酶1mRNA及其蛋白在丹参＋UW液组中较UW组表达更明显,在ZnPP预处理组中表达明显受到抑制（P〈0.05）。丹参＋UW液组肝脏Suzuki标准评分明显低于ZnPP预处理组及UW液组（P〈0.05）。表明丹参能上调同种异体的大鼠移植肝脏中血红素氧合酶1mRNA及其蛋白的表达,减轻供肝缺血-再灌注损伤,保护移植大鼠肝脏。     

高渗盐水对缺血/再灌注损伤肝脏血红素加氧酶-1表达的影响

目的 探讨高渗盐水预处理对肝脏缺血／再灌注损伤的保护作用及其机制。方法 25只SD大鼠随机分为假手术组、血红素加氧酶-1（HO-1）抑制剂锌原卟啉（ZnPP）组、缺血／ig灌注组、高渗盐水预处理组及ZnPP干预组，每组5只。建立大鼠局部肝脏缺血／再灌注损伤模型，于缺血／再灌注后6h测定血清丙氨酸转氨酶（ALT）活性、肿瘤坏死因子-α（TNF-α）含量、肝组织髓过氧化物酶（MPO）活性及肝组织内皮素1（ET1）含量；采用逆转录-聚合酶链反应（RTPCR）和蛋白质免疫印迹法（Westernblot）检测肝组织HO-1mRNA和蛋白表达；光镜和电镜下观察肝脏病理学改变及肝窦情况。观察使用ZnPP后，高渗盐水预处理对肝脏缺血／再灌注损伤的保护作用。结果 肝脏缺血／再灌注后血清ALT活性、TNF-α含量及肝组织MPO活性、ET-1含量均明显升高（P均d0．01），HO-1mRNA和蛋白表达明显增强。高渗盐水预处理明显增强缺血／再灌注后肝脏HO-1mRNA及蛋白表达，降低血清ALT、TNF-α水平及肝组织MPO活性和ET-1含量，肝脏微循环明显改善；使用ZnPP以后，高渗盐水预处理的保护作用消失。结论 高渗盐水预处理通过增强HO-1表达，对肝脏缺血／再灌注损伤产生保护作用。     

谷氨酰胺对内毒素血症大鼠肠道损伤的保护作用及对血红素加氧酶-1表达的影响

目的 探讨谷氨酰胺(Glu)对内毒素血症大鼠肠道损伤的保护作用以及对血红素加氧酶-1(HO-1)表达的影响.方法 按随机数字表法将32只雄性SD 大鼠分为正常对照组、模型组、Glu组和Glu+锌原卟啉(ZnPP)组,每组8只.腹腔注射内毒素脂多糖(LPS)10 mg/kg制备内毒素血症动物模型.Glu组注射LPS前12 h灌胃Glu 1 g/kg;Glu+ZnPP组注射LPS前12 h灌胃Glu 1 g/kg,注射LPS前1 h静脉注射ZnPP 10 mmol/kg.术后12 h取回肠组织,测定髓过氧化物酶(MPO)活性及肿瘤坏死因子-α(TNF-α)、白细胞介素-10(IL-10)含量,并进行肠组织学评分;用免疫组化法检测回肠组织HO-1表达.结果 与正常对照组比较,模型组回肠组织学评分、MPO活性及TNF-α、IL-10含量显著升高[组织学评分(分):3.3±0.4比1.1±0.6,MPO活性(U/g):0.40±0.08比0.26±0.07,TNF-α含量(ng/g):25.2±6.9比6.5±2.8,IL-10含量(ng/g):27.6±10.2比5.7±2.9,均P<0.01];HO-1表达较低.与模型组比较,Glu组组织学评分、MPO活性和TNF-α含量明显减低[组织学评分(分):1.6±0.5比3.3±0.4,MPO活性(U/g):0.25±0.05比0.40±0.08,TNF-α含量(ng/g):13.4±3.2比25.2±6.9,均P<0.01],IL-10含量(ng/g)显著升高(47.3±5.5比27.6±10.2,P<0.01),HO-1表达明显增加.Glu+ZnPP组与模型组各指标比较差异无统计学意义.结论 Glu能明显增强内毒素血症大鼠肠组织HO-1表达,明显减轻肠道炎症反应,从而保护肠黏膜.

Abstract：

Objective To investigate the protective effect of glutamine (Glu) pretreatment on intestinal injury induced by endotoxin and expression of heme oxygenase-1 (HO-1) in rats.Methods Thirty-two male Sprague-Dawley (SD) rats were randomly divided into four groups (n=8 in each group): normal control group, model group, Glu group and Glu+zinc protoporphyrin (ZnPP) group. In model group, endotoxemia was produced by intraperitoneal injection of lipopolysaccharide (LPS, 10 mg/kg). In Glu group, the rats received intragastraiclly 1 g/kg of Glu 12 hours before LPS intraperitoneal injection. In Glu+ZnPP group, the rats received 1 g/kg of Glu by gavage 12 hours before LPS intraperitoneal injection and ZnPP 10 mmol/kg intravenously via tail vein 1 hour before LPS injection. The distal ileum was harvested in full thickness 12 hours after LPS injection. The myeloperoxidase (MPO) activity, tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) in the intestine were determined, the pathologic changes were observed and expressed in Chiu grade. The expression of HO-1 was evaluated by immunohistochemistry method. Results Compared with normal control group, the Chiu grade, MPO activity, the content of TNF-α and IL-10 were significantly increased in model group [Chiu grade: 3.3±0.4 vs. 1.1±0.6, MPO activity (U/g): 0.40±0.08 vs. 0.26±0.07, TNF-α (ng/g): 25.2±6.9 vs. 6.5±2.8, IL-10 (ng/g): 27.6±10.2 vs. 5.7±2.9, all P<0.01], and the expression of HO-1 was decreased. Compared with model group, the Chiu grade, MPO activity, the content of TNF-α in Glu group were significantly decreased [Chiu grade: 1.6±0.5 vs. 3.3±0.4, MPO activity (U/g): 0.25±0.05 vs. 0.40±0.08, the content of TNF-α (ng/g): 13.4±3.2 vs. 25.2±6.9, all P<0.01], while the level of IL-10 (ng/g) elevated (47.3±5.5 vs. 27.6±10.2, P<0.01), and the expression of HO-1 was increased. There was no difference in above mentioned indexes between model group and Glu+ZnPP group. Conclusion Glu pretreatment significantly ameliorates the expression of HO-1 of intestinal tissue induced by LPS in rats, and intestinal mucosa is protected with alleviation of inflammatory reaction in intestinal tract.     

Exogenous administration of heme oxygenase-1 by gene transfer provides protection against hyperoxia-induced lung injury

Heme oxygenase-1 (HO-1) confers protection against a variety of oxidant-induced cell and tissue injury. In this study, we examined whether exogenous administration of HO-1 by gene transfer could also confer protection. We first demonstrated the feasibility of overexpressing HO-1 in the lung by gene transfer. A fragment of the rat HO-1 cDNA clone containing the entire coding region was cloned into plasmid pAC-CMVpLpA, and recombinant adenoviruses containing the rat HO-1 cDNA fragment Ad5-HO-1 were generated by homologous recombination. Intratracheal administration of Ad5-HO-1 resulted in a time-dependent increase in expression of HO-1 mRNA and protein in the rat lungs. Increased HO-1 protein expression was detected diffusely in the bronchiolar epithelium of rats receiving Ad5-HO-1, as assessed by immunohistochemical studies. We then examined whether ectopic expression of HO-1 could confer protection against hyperoxia-induced lung injury. Rats receiving Ad5-HO-1, but not AdV-betaGal, a recombinant adenovirus expressing Escherichia coli beta-galactosidase, before exposure to hyperoxia (>99% O2) exhibited marked reduction in lung injury, as assessed by volume of pleural effusion and histological analyses (significant reduction of edema, hemorrhage, and inflammation). In addition, rats receiving Ad5-HO-1 also exhibited increased survivability against hyperoxic stress when compared with rats receiving AdV-betaGal. Expression of the antioxidant enzymes manganese superoxide dismutase (Mn-SOD) and copper-zinc superoxide dismutase (CuZn-SOD) and of L-ferritin and H-ferritin was not affected by Ad5-HO-1 administration. Furthermore, rats treated with Ad5-HO-1 exhibited attenuation of hyperoxia-induced neutrophil inflammation and apoptosis. Taken together, these data suggest the feasibility of high-level HO-1 expression in the rat lung by gene delivery. To our knowledge, we have demonstrated for the first time that HO-1 can provide protection against hyperoxia-induced lung injury in vivo by modulation of neutrophil inflammation and lung apoptosis.     

血红素氧合酶-1在百草枯中毒鼠肺组织中的表达及三七总皂甙的保护作用

目的探讨急性百草枯(PQ)中毒鼠肺组织病理损伤和肺组织血红素氧合酶-1(HO-1)的表达及三七总皂甙(PNS)的保护作用。方法 150只SD雄性鼠分为正常对照组(C组)30只、PQ中毒组(PQ组)60只及PNS组60只。PQ组和PNS组一次性灌胃PQ 25 mg/kg染毒,C组给予等体积生理盐水灌胃。其中PNS组于染毒前15 min以PNS 50 mg/kg阴茎静脉注射保护,以后1次/d给药直至处死前;PQ组、C组分别在同时间点给予等体积生理盐水。观察各组大鼠在中毒后6、12 h,1、3、5、7 d肺组织病理改变,采用蛋白质印迹法分析肺组织HO-1蛋白表达和反转录-聚合酶链反应方法测定鼠肺组织HO-1 mRNA的表达。结果 C组HO-1蛋白和HO-1 mRNA绝大多数标本有弱表达,个别标本不表达;与C组相比PQ组及PNS组HO-1蛋白和HO-1 mRNA表达增强,差异有统计学意义(P<0.05);PQ组HO-1蛋白和HO-1 mRNA的表达在1 d达高峰之后下降,第3天基本恢复到C组水平;PNS组与PQ组相似,但在6 h、12 h、1 d及3 d高于PQ组,差异有统计学意义(P<0.05),至第5天和第7天二者相比差异无统计学意义(P<0.05)。PQ组肺组织病理损伤评分在6、12 h,1、3、5、7 d各亚组均高于PNS相应组,差异有统计学意义(P<0.05),C组肺组织病理大致正常,与PQ组及PNS组相比,差异有统计学意义(P<0.001)。结论 HO-1参与PQ中毒所致急性肺损伤,PNS对PQ中毒所致急性肺损伤有保护作用。     

内毒素预处理对内毒素血症大鼠肝损伤的保护作用

目的 探讨内毒素预处理对内毒素血症大鼠肝损伤的保护作用.方法 采用直接注射内毒素的方法建市大鼠急性内毒素血症模型.雄性Wistar人鼠72只,随机分成三组:生理盐水对照组(N组,n=24只)、内素脂多糖(IPS)(L组,n=24只)和LPS预处理组(P组,n=24只),每组义按时间分为2 h组、4 h组、6 h组、12 h组4个亚组,每个亚组6只.P组:首次经腹腔注射LPS 0.25mg/kg;24 h后再经腹腔注射IPSO.5 mg/kg,其余两组给予等容量生理盐水.第二次腹腔注射72 h后,L组和P组经尾静脉一次注射LPS 10 mg/kg,N组给予等量生理盐水,L组和P组在注射LPS后2,4,6,12 h,N组在注射最后一次NS后2,4,6,12 h,各取6只取肝组织制成匀浆检测Toll样受体4(Toll likereceptor-4,TLR-4)、核因子-кB(nuclear factor kappa B,NF-кB)、肿瘤坏死因子-α(tulnor necrosis factor-a,TNF-α)和丙二醛(malondiahtehyde,MDA),抽血检测谷丙转氨酶(ALT),谷草转氨酶(ASF),取肝脏(肝左上叶)用10%的中性甲醛固定.采用SPSS 13.0统汁软件进行单因素方差分析.结果 内毒素血症时符时间点肝脏组织TLR-4,NF-кB和TNF-α浓度较对照组显著升高,而内毒素预处理后则有明显下降,其中内毒素血症时4 h组肝脏组织TLR-4,NF-кB和TNF-α分别为(38.76±0.67),(170.82±31.40),(293.16±49.49)和(6.263±0.351),显著高于对照组(P＜0.05),而内毒素预处理后上述指标降至(22.32±1.35),(135.55±26.44)和(234.23±44.96),差异有统计学意义(P＜0.05).结论 内毒素预处理可减轻内毒素血症时的肝损伤,其机理可能与肝组织TLR-4,NF-кB和TNF-α的表达减少有关.     

硫化氢逆转脂多糖诱导大鼠肺动脉低反应性以及与一氧化碳的关系

目的 观察整体水平应用硫化氢(H2S)后脂多糖(LPS)诱导的离体肺动脉对H2S舒张反应的变化及其与一氧化碳(CO)的关系.方法 将48只大鼠按照随机数字表法分为对照组[给予生理盐水(NS)]、LPS组、H2S供体硫氢化钠(NaHS)+LPS组和NaHS+NS组4组,每组12只.采用经大鼠气管内滴注LPS(0.8 ml/kg)染毒;NaHS±+LPS组和NaHS±NS组滴注LPS或NS之前10 min和之后2 h腹腔注射NaHS各0.5 ml(28 μmol/kg).各组取6只大鼠于染毒后12 h制备肺动脉环(PARs),采用离体血管环张力测定技术检测用血红素氧合酶-1(HO-1)抑制剂锌原卟啉Ⅸ(ZnPPⅨ)孵育前后PARs对累积浓度NaHS的舒张反应变化;各组另取6只大鼠于染毒后12 h检测出肺血(EPB)和入肺血(APB)中碳氧血红蛋白(COHb)含量,以其差值反映肺循环CO生成的水平.结果 与对照组相比,滴注LPS后PARs对NaHS的最大舒张反应百分比明显降低[(75.72±7.22)%比(96.40±4.40)%,P＜0.01＝;用ZnPPⅨ孵育PARs后,LPS诱导的PARs对NaHS舒张反应进一步降低[(62.91±8.22)%比(75.72±7.22)%,P＜0.01＝.腹腔注射NaHS可明显逆转LPS诱导的PARs对NaHS的低反应性,PARs对NaHS的最大舒张反应百分比明显升高[(94.65±8.45)%比(75.72±7.22)%,P＜0.01＝;但用ZnPPⅨ孵育PARs后,PARs对NaHS的舒张反应较孵育前显著下降[(83.75±9.76)%比(94.65±8.45)%,P＜0.01＝.NaHS+NS组中PARs对NaHS的舒张反应与对照组相比无明显差异,且在ZnPPⅨ孵育前后也无明显变化.COHb检测结果显示,与对照组相比,滴注LPS后APB和EPB中COHb水平的差值明显增高[(3.12±0.48)%比(2.12±0.32)%,P＜0.05＝;腹腔注射NaHS后,COHb水平的差值[(4.03±0.56)%]较LPS组进一步升高(P＜0.01＝.结论 腹腔注射H2S可以改善LPS诱导的离体肺动脉对H2S的低反应性,其机制可能与增强肺动脉HO-1/CO体系有关.

Abstract：

Objective To explore the effect of hydrogen sulfide (H2S) on abnormal pulmonary artery reactivity induced by lipopolysaccharide (LPS) and its relationship with carbon monoxide (CO). Methods Forty-eight rats were divided into four groups randomly according to table of random number: control group (normal saline, NS), LPS group, a donor of H2S sodium hydrosulfide (NaHS)+LPS group, and NaHS+NS group (n=12 in each group). Rats were given LPS by intratracheal instillation (0. 8 ml/kg). 0. 5 ml of NaHS (28 μmol/kg) was injected intraperitoneally 10 minutes before LPS or NS instillation and 2 hours after LPS or NS instillation in NaHS+LPS and NaHS+NS groups. Twelve hours after instillation of LPS, 6 rats from each group were sacrificed. The pulmonary artery rings (PARs) were prepared and the changes in cumulative relaxation response of PARs to NaHS were detected before and after incubation with an inhibitor of heme oxygenase-1 (HO-1) zinc protoporphyrin Ⅸ (ZnPP Ⅸ ) using isolated vascular ring tension detecting technique. Twelve hours after LPS instillation, the remaining 6 rats in each group were sacrificed, and the contents of carboxyhemoglobin (COHb) in efferent pulmonary blood (EPB) and afferent pulmonary blood (APB) were measured, and the difference between the contents of COHb in EPB and that of APB was calculated to represent content of CO from pulmonary circulation. Results In the present study, compared with control group, after the instillation of LPS the percentage of relaxation response of PARs to NaHS was significantly declined [(75. 72±7. 22)% vs. (96. 40±4. 40)%, P＜0. 01]. After being incubated with ZnPP Ⅸ, the decreased relaxation response of PARs to NaHS induced by LPS was further depressed [(62. 91 ±8. 22) % vs. ( 75. 72 ± 7. 22) %, P ＜ 0. 01]. Administration of NaHS intraperitoneally reversed the hyporesponsiveness of PARs to NaHS, the percentage of relaxation response of PARs to NaHS was significantly increased [(94.65± 8.45)% vs. (75.72 ± 7.22)%, P＜0.01]. However ZnPP Ⅸ also attenuated the effect [(83. 75 ± 9. 76)% vs. (94. 65 ± 8. 45)%, P ＜ 0. 01]. NO significant changes were observed between NaHS+NS group and control group, also between the results before and after ZnPP Ⅸincubation. Compared with control group, the difference between the contents of COHb in EPB and that of APB increased after instillation of LPS [(3. 12±0. 48)% vs. (2. 12±0. 32)%, P＜0. 05], which further increased after intraperitoneal administration of NaHS [(4.03 ± 0. 56) %, P ＜ 0. 01]. Conclusion The results suggested that intraperitoneal administration of H2S could reverse hyporesponsiveness of PARs to H2S induced by LPS, and the result might be related to an intensification of HO-1/CO system in pulmonary artery tissue.     

Role of heme oxygenase-1 in polymyxin B-induced nephrotoxicity in rats

Polymyxin B (PMB) is a cationic polypeptide antibiotic with activity against multidrug-resistant Gram-negative bacteria. PMB-induced nephrotoxicity consists of direct toxicity to the renal tubules and the release of reactive oxygen species (ROS) with oxidative damage. This study evaluated the nephroprotective effect of heme oxygenase-1 (HO-1) against PMB-induced nephrotoxicity in rats. Adult male Wistar rats, weighing 286 ± 12 g, were treated intraperitoneally once a day for 5 days with saline, hemin (HO-1 inducer; 10 mg/kg), zinc protoporphyrin (ZnPP) (HO-1 inhibitor; 50 μmol/kg, administered before PMB on day 5), PMB (4 mg/kg), PMB plus hemin, and PMB plus ZnPP. Renal function (creatinine clearance, Jaffe method), urinary peroxides (ferrous oxidation of xylenol orange version 2 [FOX-2]), urinary thiobarbituric acid-reactive substances (TBARS), renal tissue thiols, catalase activity, and renal tissue histology were analyzed. The results showed that PMB reduced creatinine clearance (P < 0.05), with an increase in urinary peroxides and TBARS. The PMB toxicity caused a reduction in catalase activity and thiols (P < 0.05). Hemin attenuated PMB nephrotoxicity by increasing the catalase antioxidant activity (P < 0.05). The combination of PMB and ZnPP incremented the fractional interstitial area of renal tissue (P < 0.05), and acute tubular necrosis in the cortex area was also observed. This is the first study demonstrating the protective effect of HO-1 against PMB-induced nephrotoxicity.