SOD模型配合物MSODa对大鼠骨骼肌缺血再灌注损伤的保护作用

目的：研究SOD模型配合物MSODa对骨骼肌缺血再灌注后的保护作用及其机制，方法：将96只Wistar大鼠建立后肢缺血再灌注模型，按手术先后随机分为正常对照组（1组），缺血再灌注组（2组），生理盐水组（3组）和MSODa组（4组），2－4组分别在缺血4h后，再灌注1，2，4，8，12h末，测定血浆中的丙二醛（MDA），骨骼肌组织中的髓过氧化物酶（MPO），白细胞上β2整合素（CD11b/CD18)和骨骼肌血管中细胞间粘附分子（ICAM）－1的表达情况及各组的组织学改变。结果：第2组各时间点MDA，MPO，CD11h/CD18,ICAM-1的表达均较正常对照组显著升高，骨骼肌组织的损伤也随再灌注时间的延长而逐渐加重，第4组则表现为上述变化被明显抑制。结论：MSODa通过减少自由基的生成，抑制粘附分子的表达而减轻骨骼肌缺血再灌注损伤。     

缺血后处理对骨骼肌缺血再灌注后肺损伤保护作用的机制

目的：探讨缺血后处理（I-postC）对大鼠双侧后肢骨骼肌缺血再灌注（I/R）后肺损伤的保护作用及机制。方法：阻断肾下腹主动脉建立大鼠双侧后肢骨骼肌I/R损伤模型。48只大鼠随机分为3组：I/R组、缺血预处理（IPC）组及I-postC组,每组16只。分别于再灌注后12、24h各处死8只,取肺组织标本,观察肺组织形态学、湿/干重比、丙二醛（MDA）及髓过氧化物酶（MPO）的变化。原位杂交和RT-PCR方法检测肺组织中细胞间黏附分子（ICAM）-1mRNA的表达,Western blot检测ICAM-1蛋白表达。结果：再灌注12或24h后I/R组有明显的弥散功能障碍,表现为间质浸润细胞增多并伴有明显水肿。IPC组和I-postC组的各项指标均较I/R组明显降低,差异有统计学意义（P〈0.01）,但2组之间差异无统计学意义（P〉0.05）。结论：I-postC可以减轻大鼠双侧后肢骨骼肌I/R后肺损伤,与IPC可能存在共同的作用机制。     

异氟醚、七氟醚和地氟醚预处理对脑缺血再灌注损伤大鼠海马CBS/H2S、iNOS/NO和HO-1/CO的影响

目的 研究异氟醚、七氟醚和地氟醚预处理对脑缺血再灌注损伤大鼠海马CBS／H，S、iNOS／NO和HO-1／CO的影响，探讨吸入麻醉药脑保护作用的机制。方法30只Wistar大鼠随机分为5组（n=6）：对照组（C组）、脑缺血再灌注组（I／R组）、异氟醚组（I组）、七氟醚组（S组）和地氟醚组（D组）。采用四动脉阻断法建立大鼠全脑缺血再灌注模型。Ⅰ组、S组和D组夹闭两侧颈总动脉前分别吸入氧气＋0．65MAC的异氟醚、七氟醚和地氟醚30min，C组和I／R组吸入氧气。缺血20min，再灌注12h后处死大鼠，取海马，测定大鼠海马组织中HS、NO、CO、cAMP和cGMP含量和CBS，iNOS和HO活性以及CBS—mRNA、iNOS，mRNA和HO—1-mRNA的表达水平；电镜下观察海马线粒体的变化。结果与C组相比，I／R组海马组织CO、H2S、NO、cAMP、cGMP含量和HO、CBS、iNOS活性升高，CBS—mRNA、iNOS-mRNA和HO-1-mRNA表达升高，海马神经细胞线粒体变性率升高（P〈0．01）；与I／R组相比，Ⅰ组、D组和S组CO含量和HO活性升高，H2S、NO、cAMP含量和CBS、iNOS活性降低，CBS—mRNA和iNOS-mRNA表达降低而HO-1-mRNA表达升高，线粒体变性率降低（P〈0．05或0．01）。结论 异氟醚、七氟醚和地氟醚预处理可通过抑制CBS／142S、iNOS／NO，激活HO-1／CO，减轻了大鼠脑缺血再灌注损伤。     

缺血预处理对肾脏的保护作用及其机制的实验研究

目的：在肾脏缺血预处理的动物实验模型中，探讨缺血预处理对肾脏的保护作用及其机制。方法：将36只小白兔随机分为4组，即对照组，缺血预处理组（IP），缺血再灌注组（I／R）和缺血预处理后再灌注组（IP＋I／R），分别检测各组动物血液中肌酐（Cr)和一氧化氮（NO）浓度，肾组织中一氧化氮合酶（NOS,eNOS，iNOS,nNOS)在肾组织中的表达及组织学变化。结果：急性肾缺血60min再灌注60min时，发现IP组及IP＋I／R组血液中Cr浓度变化与对照组之间差异无显著性意义（P＞0．05），但明显低于I／R组（P＜0．05），在IP组和IP＋I／R组血液中，NO浓度明显高于对照组和I／R组，eNOS阳性表达在IP组和IP＋I／R组明显高于I／R组和对照组（P＜0．01），iNOS和nNOS在肾组织中未见明显表达，组织学变化发现I／R组肾细胞发生明显变性坏死，而IP组和对照组未见明显改变，结论：缺血预处理在肾脏缺血再灌注中具有保护作用。而NOS可能参与了该作用机制。     

TLR4和NF-κB在大鼠肾缺血再灌注损伤中的表达及意义

目的：观察大鼠肾缺血再灌注损伤后Toll样受体4（TLR4）和核因子-κB（NF-kB）的表达变化及其关系.方法：将40只SD大鼠随机等分为假手术组（S组）和肾缺血再灌注损伤组（I/R组）,建立肾缺血再灌注模型.在肾缺血再灌注后24 h切取肾脏.采用免疫组织化学法观察TLR4蛋自及NF-κB蛋白在肾脏组织中的表达变化及其相关性 采用半定肇逆转录-聚合酶链反应（RT-PCR）检测两组肾组织中TLR4、NF-κB的mRNA水平表达变化.结果：TLR4蛋白在S组大鼠肾小管细胞中有少量表达,在I/R组24 h后肾组织中表达明显增加,与S组比较,差异有统计学意义（P〈0.05）.NF-κB P65蛋白在S组大鼠肾小管细胞胞浆和少量胞核中有表达.在I/R组24 h后肾小管细胞胞浆和胞核均可见NF-κB P65明显表达.差异有统计学意义（P〈0.01）.TLR4和NF-κB在肾缺血再灌注损伤组织中的表达具有明显的相关性.I/R组中的TLR4 mRNA、NF-κB mRNA表达均较S组上调,差异有统计学意义（P〈0.05）.结论：大鼠肾缺血冉灌注损伤后,肾组织TLR4和NF-κB P65的表达明显上调,且有明显的相关性.TLR4有可能通过激活NF-κB继而引起下游的炎症因子募集,介导肾缺血再灌注损伤.     

葛根素对大鼠肝缺血再灌注损伤脑组织c-fos和Bcl-2表达的影响

目的：观察肝缺血再灌注损伤时c-fos、Bcl-2与脑细胞凋亡的关系及葛根素对其影响的可能机制。方法：建立肝缺血再灌注损伤动物模型。选健康雄性SD大鼠56只,随机分为对照组、缺血30min组（I组）、缺血30min即刻再灌注组（I/R组）、缺血30min再灌注1h组（I/R1h）、缺血30min再灌注2h组（I/R2h）、30min再灌注4h组（I/R4h）及葛根素预处理组（PUE＋I/R4h组）,每组8只。观缺血察各组肝、脑HE染色;应用免疫组织化学方法测定各组大鼠脑组织c-fos、Bcl-2的表达;应用原位细胞凋亡法测定脑细胞凋亡。结果：I/R2h组、I/R4h组肝组织中散在分布大量炎症细胞,肝细胞明显肿胀,有的呈空泡状变性,肝脏结构紊乱;PUE＋I/R4h组上述改变明显改善。I/R2h、I/R4h组脑组织水肿明显,PUE＋I/R4h组明显改善。与对照组比较,其余各组脑组织c-fos表达均增高﹙P〈0.01）,I/R4h组水平最高,PUE＋I/R4h组较I/R1h组、I/R2h组、I/R4h组明显降低（P〈0.01）。与对照组比较,其余各组脑组织Bcl-2表达增高（P〈0.01）,I/R4h组与I/R2h组差异无统计学意义﹙P〉0.05）,PUE＋I/R4h组较对照组、组表达增多（P〈0.01）,较I/R1h组、I/R2h组、I/R4h组明显降低（P〈0.01）。I组、I/R组细胞I凋亡指数较对照组明显增加（P〈0.01）,随着再灌注时间的延长细胞凋亡指数逐渐增加。PUE＋I/R4h组较I/R2h组、I/R4h组明显降低（P〈0.01）。结论：肝缺血再灌注损伤可引起脑组织的损伤及脑细胞凋亡。随着再灌注时间的延长,脑组织中c-fos表达增高,脑细胞凋亡与c-fos的表达有关。Bcl-2在缺血期发挥了抑凋亡的作用,随着再灌注时间的延长,其作用减弱,脑细胞凋亡指数增加。葛根素可能通过抑制c-fos的表达、增加Bcl-2的表达发挥减轻肝缺血再灌注损伤所致脑细胞凋亡的作用。     

白藜芦醇对肝脏缺血再灌注损伤的保护作用

摘要：探讨白藜芦醇对肝脏缺血再灌注损伤的防护作用。将雄性SD大鼠随机分为空白对照组、缺血再灌注组（I/R组）、I/R加生理盐水处理组和I/R加白藜芦醇处理组。观察肝脏缺血40 min再灌注1，3，6，12h后血清谷丙转氨酶（ALT）、谷草转氨酶（AST）及肝组织丙二醛（MDA）含量的变化以及肝组织病理学改变。结果示肝脏I/R后血清ALT，AST及肝组织MDA含量均显著升高，肝脏缺血再灌注前用白藜芦醇15 mg/kg者，血清ALT，AST及肝组织MDA含量均明显降低，且肝组织病理学损害明显减轻。结果表明白藜芦醇对肝脏I/R损伤具有保护作用     

氯胺酮对兔肺缺血/再灌注损伤后细胞凋亡和Caspase-3mRNA表达的影响

目的 观察氯胺酮对兔肺缺血/再灌注损伤后细胞凋亡和Caspase-3 mRNA表达的影响.方法 90只兔建立单肺缺血再灌注模型后,被随机分成3组（每组30只）：对照组（C组）、缺血/再灌注组（I/R组）和氯胺酮组（KET组）.每组30只兔子又平均分成再灌注后1小时、3小时、5小时组.检测各组超氧物歧化物（SOD）活性、丙二醛（MDA）浓度、肿瘤坏死因子α（TNF-α）含量和凋亡指数（AI）变化.图像分析TUNEL染色和原位杂交对肺细胞凋亡及Caspase-3mRNA表达.结果各相同时间点I/R组比C组SOD活性显著降低（P〈0.01）,而MDA、TNF-α含量和AI明显升高（P〈0.01）;与I/R组比较,相同时间点KET组SOD活性升高,而MDA、TNF-α含量和AI则有不同程度降低（P〈0.01或P〈0.05）.肺再灌注后TUNEL法检测阳性细胞主要分布在肺泡上皮细胞和血管内皮细胞,Caspase-3 mRNA表达主要分布在血管内皮细胞;每个时间点I/R组Caspase-3 mRNA表达相比C组显著增加,同时肺细胞凋亡也显著增加.然而,使用氯胺酮后,两者都有明显减少.结论氯胺酮可通过减少缺血/再灌注后MDA、TNF-α含量,提高SOD活性,降低caspase-3 mRNA表达而抑制肺细胞凋亡,减轻再灌注后兔肺损伤.     

TLR4表达在大鼠小肠缺血再灌注损伤中的改变及意义

目的:观察大鼠小肠缺血再灌注（I/R）损伤后小肠组织TLR4的表达及其与炎症因子水平变化的关系。方法:雄性SD大鼠90只,随机分为正常对照（N）组、假手术（S）组、小肠部分缺血/再灌注损伤（肠I/R）组。分别于缺血再灌注后6，12，24,48 h检测各组小肠组织TLR4mRNA的表达，门静脉血清中TNF-α和IL-6水平，并进行相关性分析。用免疫组化法观察TLR4在小肠组织中的表达和分布。结果:（1）肠I/R组TLR4mRNA表达上调,于I/R12 h最强,阳性细胞主要是小肠黏膜细胞;（2）I/R组门静脉血清中IL-6及TNF-α浓度与N组相比各时点均明显增高（P<0.01）;在I/R24 h后达到峰值，与S组比较差异亦有显著性 (P< 0.01);（3） 肠I/R组门静脉IL-6及TNF-α浓度的增高与小肠TLR4mRNA表达的上调呈正相关（r=0.752，r=0.812;均P<0.01）;（4）免疫组化法显示小肠黏膜细胞表面TLR4表达明显增强。结论:大鼠小肠I/R损伤后,小肠组织TLR4的表达上调可能是导致肠黏膜免疫屏障功能下降的机制之一，也可能是系统性炎症反应的始动环节。     

重组人促红细胞生成素对骨骼肌缺血再灌注损伤的保护作用

[目的]观察重组人促红细胞生成素（rHuEPO）对肢体骨骼肌缺血再灌注（IZR）损伤的保护作用。[方法]建立大鼠后肢缺血再灌注模型。40只大鼠随机均分为：假手术组（I组），I/R组（Ⅱ组），I/R＋生理盐水组（Ⅲ组），I/R＋rHuEPO组（Ⅳ组）。取血浆测定丙二醛（MDA）、肌酸磷酸激酶（CPK）和乳酸脱氢酶（LDH）含量。取骨骼肌标本测定髓过氧化酶（MP0）活性、湿重／干重比（Wet／dry）。[结果]Ⅱ组与I组比较，血浆和骨骼肌的各项生化指标显著增高（P〈0．01）；IV组血浆及骨骼肌各项测定指标较Ⅱ组相比明显降低（P〈0．01）。Ⅲ组和Ⅱ组之间比较，差异无显著意义。[结论]rHuEPO对肢体骨骼肌缺血再灌注损伤有保护作用。     

Change and role of heme oxygenase-1 in injured lungs following limb ischemia／reperfusion in rats

Lowerlimbischemiafollowedbyreperfusionisanimportantandcommonclinicalevent .Bothclinicalobservationandanimalexperimentindicatethatrestorationofbloodflowcansavethelimbsbutresultsinmultisystemorgandysfunctionevendeath .1Althoughthesystemicinflammationoflimbischemia/reperfusion (I/R )candamageanyorgan ,theonsetofthesyndromeisusuallyheraldedbythedevelopmentof pulmonarydysfunction .2 ,3Thiskindofpulmonarydysfunctionischaracterizedbyincreasedlungvascular permeabilityandpulmonaryhypertension ,whichis…     

Protective effect of hemoglobin—induced heme oxygenase—1 on injured lungs caused by limb ischemia—reperfusion in rats

OBJECTIVE: To determine the role of hemoglobin (HB) induced heme oxygenase-1 (HO-1) in injured lungs caused by limb ischemia-reperfusion (I/R) in rats. METHODS: A rat model of ischemia in the hind limbs was made by clamping the infrarenal aorta with a microvascular clip, and lung injury occurred after reperfusion. To induce the expression of HO-1 in the lungs, Hb was administrated intraperitoneally at 16 hours before reperfusion. Northern blotting and Western blotting were used to detect the expression of HO-1 in the lungs, and the carboxyhemoglobin (COHb) level in arterial blood was assayed. The effect of hemoglobin (Hb) on the injured lungs after limb I/R was determined by measuring the changes of lung histology, polymorphonuclear (PMN) count, malondialdehyde (MDA) content and wet-to-dry weight ratio (W/D). Zinc protoporphyrin (ZnPP), an inhibitor of HO, was used to determine whether HO-1 was induced by Hb after lung injury. RESULTS: Hb led to a significant increase in HO-1 mRNA and protein expression in the lungs, accompanied by the increase of COHb level in arterial blood. Compared with the sham controls, the lung PMN count, MDA content and W/D significantly increased at 4 hours after limb I/R, which reversed by the pretreatment with Hb at 16 hours before reperfusion. ZnPP blocked this protective role of Hb in the injured lungs. CONCLUSIONS: Hb can induce the lung HO-1 expression, which plays an important role in the defense against I/R induced lung injury in rats.     

CXC chemokine expression and synthesis in skeletal muscle during ischemia/reperfusion

BACKGROUND: The chemokines keratinocyte-Derived Cytokine (KC) and macrophage inflammatory protein (MIP)-2, murine equivalents of human interleukin 8, have been implicated in remote injury after acute hind limb ischemia/reperfusion (I/R). These studies were designed to determine whether the cytokines responsible for remote tissue injury are also synthesized and accumulate in the ischemic or reperfused hind limb. METHODS: B6, 129SF2/J mice were subjected to either 3 hours of unilateral hind limb ischemia alone (IA) or 3 hours of ischemia followed by 4 or 24 hours of reperfusion (I/R). After IA or I/R, experimental and control (nonischemic) contralateral hind limbs were harvested for analysis of protein content, messenger RNA (mRNA), tissue edema, and viability. RESULTS: IA did not increase KC or MIP-2 mRNA or protein levels. In contrast, I/R resulted in a 15- and 10-fold increase in KC mRNA after 4 and 24 hours of reperfusion, respectively. KC protein levels were increased 10-fold after 4 hours of reperfusion and 30-fold after 24 hours (vs IA or sham; P < .001). MIP-2 mRNA transiently increased 42-fold after 4 hours of reperfusion but decreased to basal levels after 24 hours of reperfusion. Despite the relative increase in MIP-2 mRNA by 4 hours of reperfusion, significantly increased (8- to 10 fold) MIP-2 protein levels were not detected until 24 hours of reperfusion only in the reperfused limbs. Tissue edema was increased significantly (P < .01) compared with sham after just 4 hours of reperfusion and remained increased at 24 hours. Tissue viability decreased 52% after 4 hours of reperfusion and did not change significantly by 24 hours. CONCLUSIONS: Skeletal muscle is a site of significant ongoing chemokine synthesis during reperfusion. The persistent increase in muscle chemokine levels at 24 hours of reperfusion was not associated with increased edema or injury. The role of these chemokines during reperfusion may be further investigated by local or oral administration of chemokines or chemokine receptor antagonists. CLINICAL RELEVANCE: I/R injury remains an important clinical problem across a variety of surgical specialties. In the critical care arena, serum levels of proinflammatory cytokines have been useful in predicting the mortality associated with acute respiratory distress syndrome and sepsis. In this article, the data presented indicate that murine skeletal muscle produces potent proinflammatory neutrophil and macrophage chemokines during reperfusion, but not during ischemia. These findings suggest that measurement of tissue and/or serum levels of chemokines during reperfusion may be an important adjunct to predicting tissue injury along with ongoing inflammation during the clinical course of reperfusion injury. Within the vascular system, severe inflammatory responses are usually associated with thrombotic events. New techniques to noninvasively image thrombin activation (by using magnetic resonance imaging) in reperfused limbs may coincide with the pattern of murine skeletal muscle chemokine expression in humans. The data suggest that reperfusion is when chemokine mRNA and protein synthesis increase. Within the time periods studied in these experiments, the chemokine component of the inflammatory response remained in the reperfused, rather than the systemic nonreperfused, tissue. This observation may underestimate the degree of the systemic response to ischemia because the single mouse hind limb represents only 7% of the mouse total body area, whereas the human limb represents nearly 18% of the adult body area. Despite this shortcoming, these data provide potential temporal and quantitative information regarding the location and magnitude of chemokine synthesis in skeletal muscle during reperfusion.     

缺血后处理对大鼠骨骼肌缺血再灌注损伤的影响

目的 探讨缺血后处理对大鼠骨骼肌缺血再灌注损伤的影响以及应用缺血后处理的时机.方法 将32只大鼠随机分成四组,采用切断患肢全部皮肤、肌肉和神经,保留患肢股动静脉的动物模型,通过夹闭和开放股动静脉造成骨骼肌缺血和再灌注损伤.采用测定骨骼肌缺血4 h.再灌注1 h后血清丙二醛(MDA)、骨骼肌髓过氧化物酶(MPO),再灌注6 h后骨骼肌的死亡程度来观察缺血后处理对大鼠骨骼肌缺血再灌注损伤的影响,以及再灌注5 min后应用缺血后处理是否对骨骼肌缺血再灌注损伤有保护作用.结果 对骨骼肌缺血4 h再灌注6 h的损伤,再灌注开始后即刻应用30 s缺血、30 s再通,三次循环的缺血后处理对骨骼肌的缺血再灌注损伤即有保护作用,不仅减少了骨骼肌再灌注区域中性粒细胞浸润(MPO)和血清氧自由基水平(MDA)水平,而且减少了骨骼肌的死亡程度;再灌注5 min后应用缺血后处理并没有降低骨骼肌缺血再灌注区域的MPO和血清MDA水平,也没有降低骨骼肌缺血再灌注后的死亡程度,与直接缺血再灌注组相同,对骨骼肌缺血再灌注损伤并没有保护作用.结论 骨骼肌缺血后再灌注开始前立刻应用缺血后处理对大鼠骨骼肌缺血再灌注损伤有一定的保护效果,可以减少骨骼肌缺血再灌注损伤后的死亡程度;缺血后处理应用时机非常重要,再灌注5 min后应用缺血后处理则失去对骨骼肌缺血再灌注损伤的保护作用.     

Endogenous heme oxygenase induction is a critical mechanism attenuating apoptosis and restoring microvascular perfusion following limb ischemia/reperfusion

BACKGROUND: A protective role for endogenous heme oxygenase (HO) in the initiation of remote liver injury after limb ischemia/reperfusion has been established. This study expands on our previous work by investigating the role of endogenous HO on hepatocellular injury, hepatocyte death (necrotic and apoptotic), and microvascular perfusion at protracted post-reperfusion times. METHODS: Remote liver injury was studied after 1 hour of bilateral hind limb ischemia and 3, 6, or 24 hours of reperfusion in male C57BL6 mice. Inhibition of HO was achieved with the use of chromium mesoporphrin (CrMP). Established intravital videomicroscopy techniques were used to evaluate microvascular perfusion and hepatocyte death. Hepatocellular injury was quantified by serum alanine transaminase. Apoptosis was measured by using DNA laddering, Cell Death ELISA, and caspase-3 activity. RESULTS: Although significant perfusion deficits and hepatocellular injury/death occurred after 3 hours, progression of hepatocellular death beyond 6 hours was not observed. A transient increase in apoptosis was observed at 6 hours. By 24 hours, microvascular perfusion was completely restored. This lack of progression correlated with increased HO activity, observed throughout the protocol. Administration of CrMP reduced HO activity to sham nonstressed levels, and caused increased microvascular perfusion deficits, hepatocellular injury, and hepatocyte death over 24 hours. The transient increase in apoptosis was increased in duration and magnitude in CrMP-treated animals. CONCLUSIONS: These results suggest that endogenous HO activity prevents the progression of remote liver injury after limb ischemia/reperfusion.     

Ischemic preconditioning: lack of delayed protection against skeletal muscle ischemia-reperfusion

We investigated the ability of ischemic preconditioning to induce expression of heat shock protein 70 (Hsp 70) and/or to increase muscle survival after ischemia-reperfusion in the rat hind limb. Ischemic preconditioning regimens tested were; 1 x 5 min of ischemia, 4 x 5 min of ischemia interrupted by 10 min of reperfusion, 1 x 10 min of ischemia or 2 x 10 min of ischemia interrupted by 15 min of reperfusion. Western blot analysis revealed only a modest induction of Hsp 70 at 24 h after preconditioning using the latter two protocols of 1 x 10 min of ischemia or 2 x 10 min. Used at 24 h prior to prolonged ischemia, neither protocol improved muscle survival measured at 24 h after reperfusion. In conclusion, ischemic preconditioning did not produce delayed protection from ischemia-reperfusion in this model and the study suggests that ischemic preconditioning is not a useful protective strategy against skeletal muscle necrosis in the long-term.     

缺血预处理改善骨骼肌功能的研究

目的：探讨缺血预处理法改善缺血骨骼肌功能的临床价值。方法：用ＳＤ大鼠１２只，以右后肢为动物实验模型。分为缺血组（对照组，鼠６只），即缺血４小时后再灌注１小时的方法；缺血预处理组（实验组，鼠６只），缺血过程同对照组，但在缺血前预先经过２次缺血５分钟、再灌注１０分钟的处理。实验时，分别于缺血前、缺血１、４小时及再灌注１小时时，测定两组实验侧肢体腓肠肌最大肌张力的变化。实验结束后分别测量血ＭＤＡ、ＣＰＫ及大鼠右后肢９９ｍＴｃ亚甲基二磷酸计数。结果：实验组最大肌张力的变化（缺血４小时、再灌注１小时时）较对照组有明显改善；血ＭＤＡ、ＣＰＫ及肌肉９９ｍＴｃ亚甲基二磷酸较对照组显著降低。结论：缺血预处理不仅能改善骨骼肌的缺血耐受性，而且能有效地改善骨骼肌的功能     

A noninvasive murine model of hind limb ischemia-reperfusion injury

BACKGROUND: This study describes a novel murine method of the Controlled Tension Tourniquet (CTT). The CTT applies a measured circumferential tension to hind limbs using a tourniquet attached to digital strain gauges, and is useful for investigating hind limb ischemia reperfusion (IR). MATERIALS AND METHODS: Mice were subjected to 1, 3, or 6 h of unilateral hind limb ischemia followed by either 4 or 24 h of reperfusion. Blood flow in the ischemic, reperfused, and contralateral limbs was monitored using a Laser Doppler Imager. Edema in the IR limbs was documented by changes in the wet weight to dry weight ratio. Myeloperoxidase and tetrazolium based mitochondrial activity assays indicated neutrophil infiltration and tissue viability, respectively. RESULTS: During reperfusion following 1, 4, or 6 h, flow stabilized at 100%, 53%, and 23% of baseline levels, respectively. Edema was present all in IR limbs after 4 h of reperfusion, but increased with the duration of ischemia. After 24 h of reperfusion neutrophil infiltration was equivalent in all IR limbs after all intervals of ischemia. After 24 h of reperfusion, tissue viability after 1 h of ischemia was equivalent to sham or contralateral limbs. At 3 or 6 h of ischemia and 24 h reperfusion decreased tissue viability to 40% of sham and contralateral limbs. CONCLUSIONS: The CTT provides a reproducible, noninvasive model of acute limb ischemia, which reflects the biochemical indices of microvascular injury, inflammation and flow characteristic of reperfusion injury.     

肢体缺血再灌注损伤的新型动物模型制作

[目的]用充气止血带制作肢体缺血再灌注损伤的新型动物模型,研究其对周围神经和骨骼肌损伤的影响.[方法]选择健康新西兰大白兔6个月龄,30只,体重(3.5 ±0.3) kg,雌雄不限,在家兔左侧后肢环扎充气止血带,于不同时间点松开,造成左侧后肢缺血再灌注损伤的模型.随机分为3组,每组10只.A组:对照组,B组:缺血2h,C组:缺血4h.对照组不扎充气止血带,第1、2、3、4、5、6h检测肢体的神经电生理学指标,B组、C组于再灌注(松开止血带,血供恢复后)的1、2、3、4、5、6h检测肢体的神经电生理学指标,A组于第6h观察骨骼肌的形态,B、C组于再灌注(松开止血带,血供恢复后)的第6h观察骨骼肌的形态,每组于术后第5d评估左侧后肢的行走功能.[结果]随着缺血后再灌注时间的延长,B、C和A组相比较,周围神经的潜伏期延长、波幅降低,传导速度降低,三组之间的潜伏期、波幅、传导速度差异均有统计学意义(P＜0.05),光镜观察骨骼肌可见(B、C组):横纹紊乱、肌纤维断裂、间质血管扩张充血、大量中性粒细胞浸润.[结论]经过缺血期和再灌注损伤的交互作用后,肢体的功能性损伤进一步加重,出现了不可逆的病损.该模型制作对动物的损伤较小,更贴近临床.     

Protective effect of anisodamine on reperfusion injury of skeletal muscles in rabbit

Anisodamine is an alkaloid isolated from a Chinese plant, which was subsequently synthesized. Its chemical structure is similar to atropine. It inhibits cholinergic nerve function, improves microcirculation, and was reported to have a protective effect on reperfusion injury in various organs. We used anisodamine in a rabbit model with ischemia and reperfusion injury of hind limb muscles. We evaluated its effect on skeletal muscle cells, using transmission electron microscopy, and analyzed lipid peroxidation by measuring malondialdehyde and lactate dehydrogenase blood concentrations. We found that malondialdehyde and lactate dehydrogenase concentrations after 1 hour of reperfusion were lower in animals treated with anisodamine than in controls. Damage to membrane structures and myofilaments in muscle cells was less severe after anisodamine treatment. Our findings indicate that anisodamine protects skeletal muscles with ischemia and reperfusion injury.