丹酚酸B和高氧液对兔肢体缺血再灌注氧化应激损伤的影响

目的探讨高氧液和丹酚酸B对肢体缺血再灌注损伤的影响。方法选用健康新西兰家兔24只,随机分为4组,在缺血前从耳缘静脉推注等量的生理盐水(A组)、高氧液(B组)、丹酚酸B(C组)或高氧液加丹酚酸B(D组),夹阻股动、静脉,建立肢体缺血再灌注损伤模型,在缺血前和再灌注4h抽血检测MDA、SOD,取腓肠肌作病理检测。结果血清丙二醛浓度较前明显升高,高氧液和丹酚酸B可以抑制其升高(P<0.01),两者有协同作用(P<0.01);血清超氧化物歧化酶活性较前明显降低,高氧液和丹酚酸B可以抑制其降低(P<0.01),两者有协同作用(P<0.01)。骨骼肌HE染色见:相对于对照组其他组骨骼肌损伤程度较轻,以联合用药组最轻。结论高氧液和丹酚酸B能抑制肢体缺血再灌注氧化应激损伤,而且两者有协同作用。     

丹酚酸B联合高氧液对兔肢体再灌注损伤保护作用

[目的]探讨高氧液和丹酚酸B对兔肢体再灌注损伤的保护作用.[方法]选用健康新西兰家兔24只,随机分为4组,在缺血前从耳缘静脉推注等虽的生理盐水(A组)、高氧液(B组)、丹酚酸B(C组)或高氧液加丹酚酸B(D组),夹阻股动静脉,建立肢体缺血再灌注损伤模型,在缺血前和再灌注4 h抽血检测丙二醛(MDA)和超氧化物岐化酶(SOD),取腓肠肌作病理检测.[结果]再灌注损伤后血清丙二醛浓度较前明显升高,丹酚酸B组、高氧液组以及丹酚酸B联合高氧液组的MDA升高均受到抑制(P<0.01),以丹酚酸B联合高氧液组最为明显;血清超氧化物岐化酶活性较前明显降低,丹酚酸B组、高氧液组以及丹酚酸B联合高氧液组的SOD降低均受到抑制(P<0.01),以丹酚酸B联合高氧液组最为显著.骨骼肌HE染色见丹酚酸B联合高氧液组骨骼肌损伤程度最轻.[结论]丹酚酸B联合高氧液和对兔肢体缺血再灌注损伤具有一定的保护作用,且两者有协同作用.     

丙泊酚对大鼠肢体缺血-再灌注损伤脑组织TNF-α、NF-κB表达的影响

目的 研究丙泊酚对大鼠肢体缺血-再灌注损伤脑组织肿瘤坏死因子α(TNF-α)和核因子-κ B(NF-κB)表达的影响.方法 24只SD雄性大鼠随机均分为肢体缺血-再灌注组(A组),丙泊酚组(B组)和对照组(C组).制备A组和B组的大鼠模型,采用免疫组织化学方法检测TNF-α和NF-κB的表达,并行图像分析予以半定量.结果 A、B组大鼠脑组织中TNF-α和NF-κB的表达明显增高,A组明显高于B组(P＜0.01).结论 丙泊酚对肢体缺血-再灌注引起的脑损伤有一定程度的保护作用,其机制可能与下调大鼠肢体缺血-再灌注损伤脑组织TNF-α、NF-κB的过度表达有关.     

姜黄素对骨骼肌缺血再灌注损伤的保护作用及其机制研究

目的:观察姜黄素对肢体骨骼肌缺血再灌注损伤中血浆肌酸磷酸激酶(CPK)、乳酸脱氢酶(LDH)、丙二醛(MDA)含量及骨骼肌99m锝亚甲基二磷酸钠(99mTcMDP)吸收量的影响,探讨姜黄素对肢体骨骼肌缺血再灌注损伤的保护作用及其机制。方法:制作大鼠后肢缺血再灌注损伤模型,30只大鼠随机分为假手术组、对照组、干预组。分别于再灌注1 h后测定血浆CPK、LDH、MDA含量和腓肠肌99mTcMDP吸收量变化,透射电镜观察腓肠肌超微结构变化。结果:缺血再灌注对照组和姜黄素干预组与假手术组相比,血浆CPK(7296.18±1086.53,5168.49±975.39,3014.26±963.78)、LDH(1203.66±282.53,726.56±203.65,463.85±75.32)、MDA(10.36±2.65,6.78±2.12,3.54±1.89)含量明显增高(P<0.01),99mTcMDP吸收量(16.69±3.14,11.45±2.35,9.12±1.96)明显升高(P<0.01);腓肠肌超微结构损伤明显加重;姜黄素组血浆和骨骼肌的各项指标与缺血再灌注对照组相比显著降低(P<0.01),腓肠肌超微结构损伤明显减轻。结论:姜黄素能有效降低血浆CPK、LDH、MDA含量,减少骨骼肌99mTcMDP吸收量,减轻缺血再灌注骨骼肌坏死程度和坏死范围,改善骨骼肌再灌注损伤的超微结构,说明姜黄素对骨骼肌缺血再灌注损伤具有明显的保护作用。     

肠系膜上动脉灌注高氧液对家兔肠缺血-再灌注损伤的保护作用

目的探讨术中肠系膜上动脉(SMA)灌注高氧液对家兔肠缺血再灌注损伤的保护作用及机制。方法健康家兔32只,随机均分为假手术组(S组)、缺血再灌注组(I组)、高氧液灌注组(H组)和灌注对照组(C组)。开腹夹闭SMA1h造成缺血,松夹再灌注2h制作肠缺血再灌注模型。H组在缺血期经SMA以20ml·kg-1·h-1恒速灌注高氧液1h,C组则采用同样方法输入等容量的5%葡萄糖液。再灌注2h后分别测定各组肠组织丙二醛(MDA)含量及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GPX)活性;观察光镜下各组肠粘膜组织形态学改变;测定肠粘膜组织ATP含量,并测定肠道的氧摄取率。结果小肠缺血再灌注后,肠组织MDA含量明显升高,SOD、CAT和GPX活性明显下降,光镜下肠粘膜损伤严重,肠粘膜组织ATP含量及肠道的氧摄取率均明显下降。I组与C组各参数差异无显著意义。与I组和C组相比,H组肠组织MDA含量明显降低(P<0.01),SOD、CAT和GPX活性明显升高(P<0.05),光镜下肠粘膜损伤明显减轻,肠粘膜组织ATP含量及肠道的氧摄取率均明显增加(P<0.05,P<0.01)。结论术中经SMA灌注高氧液是一种安全有效的小肠保护方法,这与高氧液中的高氧分压有关,并通过增强抗氧化酶的活性减轻肠缺血再灌注损伤。     

缺血预处理对肢体缺血再灌注损伤的影响

目的　观察缺血预处理 (IPC)对肢体缺血再灌注损伤的影响。方法　选择 2 0例需充气止血带止血进行手术的患者 ,随机分为对照组 (n =10 )和IPC组 (n =10 )。IPC组患者术前应用 3次 5min循环缺血 ,间隔 5min再灌注预处理后在止血带下进行手术 ;对照组直接在止血带下进行手术。在肢体缺血前和再灌注 30min、90min、180min分别取静脉血检测血清肌酸磷酸激酶 (CPK)、谷草转氨酶(AST)、乳酸脱氢酶 (LDH)、丙二醛 (MDA)和过氧化物歧化酶 (SOD)水平。结果　随着肢体缺血再灌注时间的延长 ,血中CPK、AST、LDH、MDA含量逐渐升高 ,而SOD活性逐渐降低。IPC组在缺血前及再灌注同时间 ,血中CPK、AST、LDH、MDA含量低于对照组 (P <0 0 5 ,P <0 0 1) ;而SOD活性高于对照组 (P <0 0 5 ,P <0 0 1)。结论　IPC能有效地减轻肢体缺血再灌注损伤程度 ,减轻脂质过氧化反应 ,提高肢体缺血耐受性     

性别因素对七氟醚后处理减轻大鼠离体心肌缺血再灌注损伤的影响

目的 探讨性别因素对七氟醚后处理减轻大鼠离体心肌缺血再灌注损伤的影响.方法 SD大鼠60只,雄雌各半,2月龄,雄性大鼠随机分为对照组(MC组)和七氟醚后处理组(MS组),雌性大鼠随机分为对照组(FC组)和七氟醚后处理组(FS组),每组15只.建立大鼠离体心脏灌注模型,采用全心缺血40 min,再灌注2 h的方法制备缺血再灌注模型.对照组心脏再灌注时给予含氧K-H缓冲液,七氟醚后处理组在复灌的前10min灌注经3%七氟醚饱和的含氧K-H缓冲液,余110 min灌注含氧K-H缓冲液.于缺血前、再灌注期间记录HR、左心室舒张末压(LVEDP)和左心室发展压(LVDP),再灌注5 min时测定冠状动脉流出液LDH活性和心肌梗死面积,再灌注10 min时测定心肌总蛋白激酶B(t-Akt)、磷酸化蛋白激酶B(p-Akt)的表达,计算p-Akt与t-Akt比值(p-Akt/t-Akt).结果 与MC组比较,MS组和FC组LVDP升高,LVEDP降低,冠状动脉流出液LDH活性降低,心肌梗死面积减小,心肌p-Akt表达上调,p-Akt/t-Akt升高(P＜0.05);与MS组比较,FS组LVDP降低,LVEDP和冠状动脉流出液LDH活性升高,心肌梗死面积增大(P＜0.05);FC组和FS组LVDP和LVEDP比较差异无统计学意义(P＞0.05).结论 七氟醚后处理减轻大鼠离体心肌缺血再灌注损伤存在性别差异,对雄性大鼠的心肌保护作用强于雌性大鼠,该差异可能与心肌Akt的活化水平有关.     

异丙酚对大鼠离体心脏缺血再灌注时NF-κB及iNOS的影响

目的 探讨异丙酚对大鼠离体心脏缺血再灌注时核因子κB(NF-κB)及诱导型一氧化氮合酶(iNOS)的影响.方法 成年SD大鼠24只,体重200～300 g,雌雄不拘,随机分为3组(n=8):对照组(C组)、缺血再灌注组(I/R组)和异丙酚组(P组).建立Langendorff离体心脏灌注模型,K-H液平衡20 min后开始实验.C组灌注K-H液110 min;I/R组灌注K-H液20 min后,全心停灌30 min,再灌注60 min;P组用含50 μmol/L异丙酚的K-H液灌注20 min,全心停灌30 min,再用含50 μmol/L异丙酚的K-H液灌注60 min.于平衡末、再灌注10 min和60 min时测定冠状动脉流出液心肌肌钙蛋白(cTnI)浓度;于再灌注60 min时测定心肌SOD活性、MDA含量、iNOS活性及NF-κB、IκB的表达水平.结果 与C组比较,I/R组再灌注期间冠状动脉流出液cTnI浓度升高,P组再灌注期间60 min时升高(P＜0.05或0.01),I/R组心肌SOD活性降低,MDA含量增多,iNOS活性升高(P＜0.01),I/R组和P组心肌NF-κB表达升高,kB表达降低(P＜0.05或0.01).与I/R组比较,P组再灌注期间冠状动脉流出液cTnI浓度、心肌MDA含量、NF-κB表达、iNOS活性均降低,心肌SOD活性和IκB表达升高(P＜0.01).结论 异丙酚可抑制心肌NF-κB的激活,降低iNOS的活性,从而减轻大鼠离体心脏缺血再灌注损伤.     

细胞穿透肽PEP-1介导血红素加氧酶-1对大鼠离体心脏缺血再灌注损伤的影响

目的 探讨细胞穿透肽PEP-1介导血红素加氧酶-1(HO-1)对大鼠离体心脏缺血再灌注损伤的影响.方法 雄性SD大鼠,体重220～280g,制备Langendorff离体心脏灌注模型,选取模型制备成功的离体心脏18个,随机分为3组(n=6):假手术组(S组)、缺血再灌注组(IR组)和PEP-1/HO-1处理+缺血再灌注组(HO-1组).IR组K-H液平衡灌注30 min后,采用停灌40 min再灌注50 min的方法制备缺血再灌注模型.HO-1组在停灌前用含50 μmol/L融合蛋白PEP-1/HO-1的K-H液平衡灌注15 min,S组采用K-H液持续灌注120 min.再灌注50 min时,收集冠脉流出液,测定肌酸激酶(CK)和乳酸脱氢酶(LDH)的活性;取心肌组织,采用Western blot法测定HO-1蛋白表达水平,采用硫代巴比妥酸比色法测定MDA含量,黄嘌呤氧化酶法测定SOD活性.结果 HO-1组心肌组织HO-1蛋白表达水平较IR组升高(P＜0.01).与S组比较,IR组和HO-1组冠脉流出液CK和LDH活性及心肌组织MDA含量升高,心肌组织SOD活性降低(P＜0.01);与IR组比较,HO-1组冠脉流出液CK和LDH活性及心肌组织MDA含量降低,心肌组织SOD活性升高(P＜0.01).结论细胞穿透肽PEP-1可将HO-1蛋白成功导入心肌组织,并减轻大鼠心肌缺血再灌注损伤.     

沉默信息调节因子1在缺血预处理减轻大鼠心肌缺血再灌注损伤中的作用

目的 探讨沉默信息调节因子1(SIRT1)在缺血预处理减轻大鼠心肌缺血再灌注损伤中的作用.方法 雄性SD大鼠48只,体重200 ～ 250 g,12周龄,采用随机数字表法,将其分为4组(n=12):假手术组(S组)、缺血再灌注组(I/R组)、缺血预处理组(IPC组)和缺血预处理+SIRT1抑制剂组(IPC+ ex527组).采用结扎左冠状动脉前降支30 min再灌注120 min的方法制备心肌缺血再灌注损伤模型,IPC组和IPC+ ex527组进行缺血预处理(缺血5 min,再灌注5 min,重复3个循环,共30 min),IPC+ ex527组分别于缺血前15 min及再灌注前1 min静脉注射ex527 1 μg/kg.分别于缺血前和再灌注120 min时采集股动脉血样,测定血清TNF-α和IL-6的浓度,处死大鼠,取心肌组织,测定乳酸脱氢酶(LDH)、肌酸激酶同工酶(CK-MB)活性、SIRT1表达和NF-κB p65乙酰化水平.结果 与S组比较,I/R组和IPC+ ex527组再灌注120 min时血清TNF-α、IL-6浓度、心肌组织LDH、CK-MB活性和NF-κB p65乙酰化水平升高,心肌组织SIRT1表达下调(P＜0.05);与I/R组比较,IPC组血清TNF-α、IL-6浓度、心肌组织LDH、CK-MB活性、NF-κB p65乙酰化水平降低,心肌组织SIRT1表达上调(P＜0.05),IPC+ ex527组上述指标差异无统计学意义(P＞0.05);与IPC组比较,IPC+ ex527组血清TNF-α、IL-6浓度、心肌组织LDH、CK-MB活性、NF-κB p65乙酰化水平升高,心肌组织SIRT1表达下调(P＜0.05).结论 SIRT1参与了缺血预处理减轻大鼠心肌缺血再灌注损伤.     

去除门静脉淤血减轻肝脏缺血再灌注损伤的实验研究

目的 探讨去除门静脉淤血对肝脏缺血再灌注损伤的影响及机制.方法 检测家兔肝脏原位冷灌注20、30、40 min后淤血的门静脉中内毒素含量变化,观察门静脉淤血去除对恢复灌流后4 h血清内毒素、丙氨酸转氨酶(ALT)、透明质酸(HA)、肝组织匀浆丙二醛(MDA)、超氧化物歧化酶(SOD)及肝组织核因子-κB(NF-κB)活性的影响.结果 门静脉淤血中内毒素含量随阻断时间延长明显升高(P＜0.01),同一阻断时间每去除2.5 ml淤血血清内毒素含量显著下降(P＜0.01).在阻断30 min和40 min组,去除门静脉淤血能降低血清ALT、HA、及肝组织匀浆MDA的含量和肝组织NF-κB活性,增加肝组织匀浆SOD活性,与不去除相比较差异有统计学意义(P＜0.05).在阻断20 min组去除门静脉淤血与不去除相比较,各检测指标差异无统计学意义(P＞0.05).结论 门静脉淤血中内毒素含量随阻断时间延长明显升高,可能是引起肝脏损伤的主要原因;去除门静脉淤血可以减轻肝脏的再灌注损伤,其机制可能与门静脉淤血去除减少内毒素吸收,进而降低肝组织NF-κB活化有关.     

Hyperoxic reperfusion exacerbates postischemic renal dysfunction

BACKGROUND: Hyperoxic reperfusion from global ischemia worsens functional outcome because of oxygen radical-mediated injury. This study tested the hypothesis that hyperoxic reperfusion would exacerbate postischemic renal dysfunction. METHODS: Twenty-nine healthy, uninephrectomized, male mongrel rabbits (Oryctolagus cuniculus) in 3 groups were subjected to 30 minutes of complete normothermic renal ischemia followed by reperfusion under hyperoxic or normoxic conditions. The groups were: hyperoxically reperfused (n = 8), normoxically reperfused (n = 8), hyperoxic sham (no ischemia, n = 5), and allopurinol-pretreated (50 mg/kg, intravenously), hyperoxically reperfused animals (n = 8). Plasma concentrations of creatinine, urea nitrogen and electrolytes were measured at 0, 24, 48, and 72 hours after ischemia and served as functional outcome markers. Histopathologic analysis of kidneys for injury was performed by an expert who was blinded to the procedures. RESULTS: Plasma creatinine in hyperoxically reperfused rabbits was significantly elevated above normoxic (P =.02) and sham (P =.003) animals by 48 hours and remained elevated to 72 hours. Plasma urea nitrogen in hyperoxically reperfused rabbits was significantly elevated above the normoxic group (P = .01), the sham group (P = .02), and the allopurinol group (P = .04) by 72 hours. These coincided with a significantly elevated histopathologic injury score in hyperoxically reperfused rabbits compared with sham (P = .019), normoxic (P = .035), and allopurinol-pretreated hyperoxically reperfused animals (P = .037). CONCLUSIONS: Hyperoxic reperfusion exacerbates renal dysfunction after 30 minutes of complete normothermic ischemia. This dysfunction may be mediated by oxygen radical-related injury.     

高氧液治疗缺血性心肌功能的研究

目的　观察高氧液对家兔烫伤后缺血性心肌功能的治疗作用并探索其机制。　方法　制作 30 %Ⅲ度TBSA家兔烫伤模型和心肌缺血模型。将动物随机分成烫伤心肌缺血高氧液治疗组 (A)、烫伤心肌缺血等渗盐水治疗组 (B)、单纯烫伤对照组 (Cb)和正常对照组 (Ch)。动态监测心功能、血液流变学、血气分析及心肌梗死 /缺血面积比值。　结果　 (1)与Ch 组相比 ,B组心功能指标明显下降 (P <0 .0 1) ,A组较B组下降幅度减轻 ,两者存在显著性差异 (P <0 .0 5 ) ;(2 )与Ch 组相比 ,各组的全血黏度 (ηb)均有显著性升高 (P <0 .0 5 ) ,尤以B组为重。A组与B组相比 ηb值有明显的下降 (P <0 .0 1) ,与Cb 组相比无显著性差异 (P >0 .0 5 ) ;(3)A组PO2 明显高于B组和C组 (Cb、Ch,P <0 .0 1) ;(4 )A组的梗死 /缺血比值明显低于B组 (P <0 .0 1)。　结论　高氧液对烫伤后心肌缺血有确切的治疗作用 ,其作用机制可能是迅速改善重要脏器的缺氧状态 ,同时降低血液黏度 ,加速侧枝循环的建立。     

肝移植术中应用S-腺苷-L-蛋氨酸对供肝热缺血损伤的影响

目的探讨术中S-腺苷-L-蛋氨酸（SAMe）加入UW液和血浆冲洗液对热缺血损伤供肝及其恢复的影响。方法建立10min热缺血大鼠肝移植模型，分为A组：UW液灌注＋乳酸钠林格氏液冲洗、B组：UW液灌注＋血浆冲洗、C组：SAMe加入UW液灌注＋血浆冲洗和D组：UW液灌注＋SAMe加入血浆冲洗4组，观察肝组织组织病理学变化和电子显微镜下超微结构变化，并检测血清AST和透明质酸。结果C组和D组术后24h血清AST均低于B组（P〈0．05）。A组术后3h和24h血清HA高于B组（P〈0．05），B组复流后3h及24h血清HA均高于C组和D组（P〈0．05）。组织病理学表现B组复流后3h和24h肝细胞损伤和微循环紊乱较C组和D组明显；超微结构表现，A组复流后3h线粒体肿胀，肝窦内皮细胞肿胀，细胞核不规则，可见内皮细胞凋亡，大部分区域肝窦状隙明显狭窄，内皮层结构模糊，红细胞淤积，受压变形，白细胞附壁，可见内皮层完整性破坏；复流后24h，可见线粒体嵴断裂，核融解。B组内皮细胞损伤较A组轻，C组和D组超微结构表现微循环紊乱和肝细胞损伤表现较B组轻。结论供肝切取术中UW液中加入SAMe灌注保存，血浆冲洗液中加入SAMe可改善热缺血供肝微循环，减轻缺血再灌注损伤，并减轻肝细胞热缺血损伤，有利于10min热缺血供肝功能的恢复。     

肢体缺血再灌流对胫前筋膜间隔压力影响的实验研究

为了观察肢体不同缺血时间再灌流后筋膜间隔的压力变化以及与血清丙二醛（ＭＤＡ）、血清肌酸液酶（ＣＰＫ）含量变化的关系,观察甘露醇对肢体缺血再灌流的保护作用,作者将１８只新西兰兔分成３组,分别观察各组术前、缺血即时、缺血期末、再灌流４、２４、７２小时筋膜间隔的压力变化以及血清ＭＤＡ、ＣＰＫ的含量变化和骨骼肌的组织学变化。结果显示：缺血时间越长,组织损伤越重,再灌流后损伤进一步加重,以再灌流２４小时到达顶点,血清ＭＤＡ、ＣＰＫ均达峰值,与筋膜间隔的压力变化一致。应用甘露醇组的变化则明显减轻。实验结果表明,肢体缺血再灌流可以导致筋膜间隔的压力增高,从而使损伤进一步加重,这种损伤以再灌流后２４小时最为严重,而甘露醇可以明显减轻组织的损伤和降低筋膜间隔的压力。     

Surgical reoxygenation injury of the myocardium in cyanotic patients: clinical relevance and therapeutic strategies by normoxic management during cardiopulmonary bypass

Cyanotic hearts are associated with depleted endogenous antioxidants (glutathione peroxidase, superoxide dismutase, and catalase), and thereby is more susceptible to myocardial ischemia/reperfusion injury during open heart surgery compared with acyanotic ones. Clinically, when surgery is performed on cyanotic infants, cardiopulmonary bypass (CPB) is usually initiated at high PaO(2), without consideration of possible cytotoxic effects of hyperoxia. The concept of "surgical reoxygenation injury of cyanotic myocardium" was proposed, wherein unintended abrupt reoxygenation of cyanotic myocardium at the onset of routine CPB causes oxygen-mediated injury, which may render the reoxygenated myocardium more susceptible to subsequent surgical ischemia/reperfusion injury and accentuates post-CPB myocardial dysfunction. The experimental studies using acute and chronic hypoxia models confirmed the role of reoxygenation injury mediated by reactive oxygen species in the pathogenesis of post-CPB myocardial dysfunction and addressed the importance of controlling PaO(2) at the onset of CPB. The clinical relevance of this injury was shown by subsequent clinical studies, which demonstrated depleted antioxidant reserve capacity and troponin release during the initial reoxygenation on hyperoxic CPB prior to cardioplegic arrest. Furthermore recent randomized clinical trials verified that hyperoxic CPB provokes biochemical multi-organ damage including myocardium, lung, liver, and brain after open heart surgery in cyanotic patients, which can be successfully reduce by normoxic CPB management (i.e., reducing PaO(2) at onset of CPB, gradual reoxygenation and controlled reoxygenation protocol). Based on these experimental and clinical studies, avoidance of using hyperoxic PaO(2) on routine CPB is strongly recommended in the cyanotic patients.     

Controlled reperfusion of ischemic extremity musculature to prevent free radical induced lesions]

Tissue injury following reperfusion represents an essential problem of reconstructive vascular surgery. Pathogenetically toxic oxygen radicals are considered to play a pivotal role. Pharmacotherapeutical approaches are based particularly on antioxidants and vasodilators. However, a standardized regimen is not yet clinically introduced. In 48 adult Lewis-rats lower limb ischemia was induced by aortal cross-clamping. Following 3.5 hours of ischemia intravascular flushing perfusion via the distal aorta with a heparinized electrolyte solution (group B). Group C received additionally oxypurinol, group D alprostadil and group E sodium selenite into the flushing solution. At 4 hours recirculation was established. After 10 min, 30 min and 24 hours of reperfusion we determined lactate, creatine kinase, lactate dehydrogenase, urea, malondialdehyde and the laser Doppler flux. At the end of the experiments biopsies were taken from M. tibialis anterior. In comparison to control animals (group A) we observed an attenuation of reperfusion injury in the groups treated with flushing perfusion. Free oxygen radical reactions measured by malondialdehyde release were significantly reduced (30 min: A-209.1 +/- 45.4, B-127.3 +/- 36.9, C-113.2 +/- 14.1, D-99.6 +/- 24.5, E-123.6 +/- 11.2 mmol/l, p < 0.05). The laser Doppler flux measurements corresponded with the biochemical analyses (30 min: A-52.4 +/- 11.1, B-48.0 +/- 11.0, C-72.6 +/- 12.0, D-74.4 +/- 13.3, E-62.6 +/- 10.8% of baseline). Histologically, treatment with alprostadil (PGE1) and oxypurinol revealed superior results. Standardized intraarterial flushing perfusion with antioxidants and vasodilators reduces reperfusion injury. Clinical trials are urgently required to confirm the experimental findings and to optimize the therapy of extremity ischemia/reperfusion injury in humans.     

Superoxide anion release (O2-) after ischemia and reperfusion.

Neutrophils have been implicated as mediators of the reperfusion injury following ischemia. In order to measure neutrophil activation, O2- was determined after 2 hr of ischemia followed by 1 hr of reperfusion (no clinical reperfusion injury) and 3 hr of ischemia followed by 1 hr of reperfusion (significant clinical reperfusion injury). Using New Zealand white rabbits, baseline blood samples were drawn from an ear artery. The right iliac and femoral arteries were exposed and clamped. Just prior to clamp release, blood was obtained from the right iliac vein (ischemia). After 1 hr of reperfusion, blood was again taken from the right iliac vein (reperfusion). Neutrophils were isolated from the blood samples. O2- was determined by the reduction of cytochrome c using a spectrophotometer. In the 2-hr group, results (expressed as mumole O2-/min/2 x 10(6) cells) were: baseline, 0.337 +/- 0.025; ischemia, 0.512 +/- 0.039;* and reperfusion, 0.634 +/- 0.064*. (*P less than .05 as compared to baseline). In the 3-hr group, results were: baseline, 0.391 +/- 0.038; ischemia, 0.413 +/- 0.051; and reperfusion, 0.258 +/- 0.043** (**P less than 0.05 as compared to 2 hr reperfusion). A significant increase in O2- was seen after 2 hr of ischemia followed by 1 hr of reperfusion. However, little O2- increase was seen after 3 hr of ischemia and a significant O2- decrease was seen after 1 hr of reperfusion. We conclude: (1) Neutrophil O2- is stimulated early in ischemia followed by reperfusion; (2) after reperfusion injury occurs (3 hr), neutrophils have been activated and O2- can no longer be stimulated; and (3) O2- in this model may be involved in the clinical reperfusion injury seen.