缺血再灌注损伤皮瓣组织中金属硫蛋白的免疫组化研究

目的：观察缺血再灌注损伤皮瓣组织中金属硫蛋白(Metallothionein MT)的表达部位及表达量的变化规律。方法：16只大鼠随机分为对照组(n=8)和缺血再灌注组(n=8)。在大鼠以腹壁浅血管为蒂的岛状皮瓣缺血再灌注模型上，用硫代巴比妥法和比色法分别测定皮瓣组织中丙二醛(MDA)含量和髓过氧化物酶(MPO)活性。观察免疫组化切片中MT的表达部位，并对切片进行图像分析，以积分光密度代表MT的含量。结果：缺血再灌注组再灌注1h和24h，皮瓣组织中MDA含量分别较对照组高46.5％、147.8％，MPO活性分别较对照组高1169．5％、408．6％，MT含量分别较对照组高119．9％、234．6％。在发生缺血再灌注损伤的皮瓣中MT表达在表皮基底层细胞、皮下组织及肉膜下组织血管壁细胞、成纤维细胞，毛囊、皮脂腺、汗腺和肌细胞的细胞浆中。结论：皮瓣发生缺血再灌注损伤后，MT表达在皮瓣组织的多种细胞内，MT含量增加可能和皮瓣在发生缺血再灌注损伤时的某些代谢产物有关。     

缺血再灌注损伤皮瓣组织中金属硫蛋白含量变化

目的　观察缺血再灌注损伤皮瓣组织中金属硫蛋白 (metallothionein ,MT)的含量变化。方法　 16只大鼠随机分为对照组 (n =8)和缺血再灌注损伤组 (n =8)。在大鼠腹壁浅血管为蒂的岛状皮瓣缺血再灌注损伤模型上 ,用10 9Cd血红蛋白饱和法和硫代巴比妥酸法测定皮瓣组织中MT及丙二醛(MDA)含量 ,比色法测定皮瓣组织过氧化物酶 (MPO )活性。结果　缺血再灌注损伤组在缺血 8h、再灌注 12h、2 4h时皮瓣组织中MDA水平分别较对照组高 41.7%、111.4%、13 5.7% ,MPO水平分别较对照组高 72 .1%、2 18.9%、2 96.0 % ,MT含量分别较对照组高 42 .6%、52 .8%、10 2 .3 % (P <0 .0 5或P<0 .0 1)。结论　皮瓣组织中MT含量增多 ,可能与皮瓣缺血再灌注损伤有关     

金属硫蛋白在心肌缺血再灌注损伤中的作用

金属硫蛋白富含半胱氨酸和金属离子，具有重金属解毒清除自由基和稳定生物膜等生理作用。作为内源性可诱导蛋白，金属硫蛋白在心肌缺血再灌注损伤中具有重要的应用前景。     

金属硫蛋白参与皮瓣缺血预处理的延迟保护作用

目的 :金属硫蛋白 (MT)参与皮瓣缺血预处理 (PC)延迟保护作用(DP)的可能性。　方法 :在猪背阔肌岛状皮瓣PC和培养肌细胞缺氧PC的模型上 ,检测PC后即刻 ,12hr和 2 4hrMT含量变化 ,观察PC后 2 4hr对再次长时间缺血 再灌注或缺氧 复氧损伤的保护作用 (皮瓣坏死范围 ,细胞存活率 ,LDH释放和细胞MDA含量 )以及用PD0 980 59抑制PC后MT含量增高对PC和DP的影响。　结果 :MT含量在PC后 12hr (肌细胞 )和 2 4hr (肌细胞和皮瓣组织 )显著增高 ,与未PC的皮瓣组织或肌细胞遭受I R或A R的损伤相比较 ,PC后 2 4hr其皮瓣坏死范围缩小 ,血浆LDH活性升高程度减轻 ,肌细胞成活率增高 ,细胞MDA含量和LDH释放均降低。用PD0 980 59抑制MT生成增多时 ,则消除了PC后的DP作用 ,上述皮瓣损伤指标接近单纯I R组或A R组 (P >0 0 5 )。　结论 :1 PC后 2 4hr皮瓣或肌细胞对再次I R或A R的损伤有保护作用 ;2 MT参与了皮瓣或肌细胞PC后的DP作用。     

硫酸锌对皮瓣缺血再灌注损伤保护作用的研究

目的 观察外源性锌对皮瓣缺血再灌注（ischemia—reperfusion，IR）损伤的保护作用，并探讨其机制。方法 48只大鼠随机分为非-IR组、IR组和补锌-IR组。在大鼠以腹壁浅血管为蒂的岛状皮瓣缺血再灌注模型上，分别测定皮瓣组织中丙二醛（MDA）含量和髓过氧化物酶（MPO）活性。观察免疫组化切片中金属硫蛋白（metallothionein，MT）的表达，并对切片进行图像分析。应用透射电镜观察皮瓣缺血再灌注损伤后超微结构的改变，观察皮瓣成活率。结果 补锌-IR组在再灌注1h和24h，皮瓣组织中MDA含量分别较IR组降低11．3％、33．2％（P〈0．05），MPO活性分别较IR组降低14．2％、22．7％（P〈0．05），MT含量分别较IR组高41．5％、44％（P〈0．01）。在补锌-IR组掀起皮瓣即刻的标本中有一定量的MT表达。MT表达在皮瓣组织多种细胞的细胞浆中。补锌-IR组皮瓣的超微结构改变较IR组减轻，皮瓣成活率较IR组升高27．2％（P〈0．05）。结论 外源性锌能诱导皮瓣内MT产生，MT通过细胞保护作用对皮瓣缺血再灌注损伤产生一定的保护作用。     

金属硫蛋白在心肌缺血再灌注损伤中的作用

金属硫蛋白富含半胱氨酸和金属离子,具有重金属解毒清除自由基和稳定生 物膜等生理作用。作为内源性可诱导蛋白,金属硫蛋白在心肌缺血再灌注损伤中具有重要的 应用前景。     

金属硫蛋白在心肌缺血/再灌注损伤中保护作用的研究进展

金属硫蛋白（metallothionein, MT）是一类富含半胱氨酸残基的低分子量金属连接蛋白,广泛存在于生物体内。心肌缺血/再灌注损伤（myocardial ischemia/reperfusion injury, MI/RI）严重威胁着心血管疾病患者生命安全,其机制尚不明确。文章描述了MT的结构及生理作用,MI/...     

脂质体携载金属硫蛋白对皮瓣继发静脉缺血再灌注损伤的作用

目的 观察脂质体包裹金属硫蛋白(MT)对岛状皮瓣继发静脉缺血再灌注损伤的保护作用。方法 在大鼠下腹部岛状皮瓣继发静脉缺血再灌注损伤模型上测定皮瓣即刻、继发缺血再灌注30min、7d后的丙二醛(MDA)含量、髓过氧化物酶(MPO)活性，继发缺血再灌注30min时血浆内皮素(ET)、乳酸脱氢酶(LDH)水平，7d后皮瓣MT的含量。结果 脂质体携载MT组明显降低皮瓣MDA、MPO、血浆ET、LDH含量，增加7d后皮瓣组织MT含量，提高皮瓣成活率。结论 脂质体包裹MT对皮瓣继发静脉缺血再灌注损伤具有良好的保护作用。     

金属硫蛋白与皮瓣缺血预处理延迟保护作用的实验研究

目的：探讨金属硫蛋白（MT）参与皮瓣缺血预处理（PC）延迟保护作用（DP）的可能性。方法：在猪背阔肌岛状皮瓣PC和培养肌细胞PC的模型上，检测PC后即刻，12h和24h MT含量变化，观察PC后24h对再次长时间缺血再灌注（I／R）或缺氧复氧（A／R）损伤的保护作用以及用丝裂素蛋白激酶抑制剂（PD098059）抑制PC后MT含量增高对PC和DP的影响。结果：MT含量在PC后12h（肌细胞）和24h（肌细胞和皮瓣组织）显著增高，与未PC的皮瓣组织或肌细胞遭受I／R或A／R的损伤相比较，PC后24h其皮瓣坏死范围缩小（P＜0．05），血浆乳酸脱氢酶（LDH）活性降低（P＜0．05），肌细胞存活率增高，细胞丙二醛（MDA）含量和LDH释放均降低（P＜0．01）。用PD098059抑制后则消除了PC后的DP作用，上述皮瓣损伤指标接近单纯I／R组或A／R组（P＞0．05）。结论：①PC后24h对皮瓣或肌细胞的再次I／R或A／R损伤具有保护作用；②MT参与了皮瓣或肌细胞PC后的DP作用。     

锌对皮瓣缺血再灌注损伤细胞保护作用的研究

目的观察外源性锌在皮瓣缺血再灌注(ischem ia-reperfus ion,IR)损伤中的细胞保护作用,并探讨其机制。方法48只健康雄性W istar大鼠,制备以腹壁浅动脉为蒂的轴型皮瓣IR模型。大鼠随机分为对照组、IR组和补锌-IR实验组,每组16只。各组分别取8只大鼠,IR组和实验组于掀起皮瓣即刻、再灌注后1 h和24 h分别于皮瓣中段边缘取全层皮瓣组织1.0 cm×0.5 cm,对照组于掀起皮瓣即刻、9 h和32 h同法取材,分别行免疫组织化学检测金属硫蛋白(m eta lloth ione in,M T)的表达部位,并对切片进行图像分析;透射电镜观察IR后超微结构的改变和皮瓣成活率;生物化学检测皮瓣组织中丙二醛(m a lond ia ldehyde,M DA)含量和髓过氧化物酶(m ye loperox idase,M PO)活性。结果掀起皮瓣即刻对照组、IR组和实验组皮瓣M DA、M PO水平相近,差异无统计学意义(P>0.05)。缺血再灌注后1、24 h,IR组M DA含量分别高于对照组62.2%和136.4%(P<0.01),高于实验组11.3%和33.2%(P<0.05);M PO活性分别高于对照组238.4%和503.4%(P<0.01),高于实验组17.9%、24.1%(P<0.05)。掀起皮瓣即刻对照组和IR组M T含量极低,无法定量分析,实验组为45.30±7.60。缺血再灌注后1、24 h,实验组M T含量分别较IR组高41.5%和44.9%(P<0.01),IR组M T含量分别较对照组高119.9%和234.6%(P<0.01)。对照组皮瓣成活率为100%,IR组皮瓣成活率为19.65%±4.38%,实验组皮瓣成活率为24.99%±5.12%,较IR组提高27.2%(P<0.05)。结论外源性锌能对皮瓣内多种细胞的IR损伤产生保护作用,可明显提高皮瓣成活率。     

缺血再灌注损伤与细胞凋亡及相关基因Bcl-2

缺血再灌注损伤是各种器官及组织移植过程中导致早期失去功能的最主要原因。近年来，越来越多的研究证实，细胞凋亡是造成移植物缺血再灌注损伤早期细胞死亡的主要方式。现将缺血再灌注损伤时细胞凋亡及相关基因B-细胞淋巴瘤／白血病-2原癌基因（B-cell lymphoma／leukemia-2．Bcl-2）以及其调控机制的相关研究进展综述如下。     

Ischemia-reperfusion injury activates innate immunity in rat kidneys

BACKGROUND: There is growing evidence of a role of the immune system in the pathophysiology of ischemia-reperfusion (I/R) injury, but the influence of I/R injury on innate immunity is still undetermined. METHODS: Sprague-Dawley rats were used. I/R injury was induced by clamping both renal arteries for 45 min, and the rats were killed 1, 3, 5, and 7 days later. Activation of innate immunity was evaluated in terms of the expression of toll-like receptor (TLR) 2 or TLR4 mRNAs and protein, by the level of the TLR ligand (heat shock protein [HSP] 70), and maturation of dendritic cells by double-label immunohistochemistry of dendritic cells for major histocompatibility complex (MHC) class II antigen. RESULTS: I/R injury increased TLR2 and TLR4 mRNA and protein expression, and they were mainly observed on renal tubular cells. I/R injury also produced endogenous TLR ligand (HSP70) on renal tubular cells. I/R injury increased not only the numbers of dendritic cells but also the production of MHC class II antigen in dendritic cells, suggesting maturation of these cells. Activation of innate immunity was observed at day 1, peaked at days 3 to 5 after I/R injury, and thereafter gradually decreased. CONCLUSIONS: I/R injury rapidly activates the innate immune response.     

Ischemia-reperfusion injury following superior mesenteric artery occlusion and strangulation obstruction

BACKGROUND: Intestinal ischemia-reperfusion injury (IRI) is a serious and common clinical entity resulting in severe tissue injury. This study was designed to compare IRI in superior mesenteric artery (SMA) occlusion and strangulation obstruction (SO). MATERIALS AND METHODS: Thirty Wistar-Albino rats were assigned randomly to three groups. In the control group, a sham operation was performed. In the SMA occlusion group, a vascular clamp was placed across the SMA to occlude arterial circulation. In the SO group, a 15-cm segment of small intestine was looped to prevent venous circulation. Sixty minutes of ischemia was followed by 60 min of reperfusion. Following reperfusion, biopsies of small intestine were taken to assess morphologic damage, tissue levels of malonyldialdehyde (MDA) as an index of lipid peroxidation reflecting oxygen free radicals (OFR) were determined, and serum biochemical analyses were performed. RESULTS: The levels of tissue MDA were significantly higher in the SO group than in the SMA occlusion group (P < 0.05). Biochemical parameters of SO and SMA occlusion groups were higher than those in the control group and there was a significant difference between the SMA occlusion and the SO models, except for ALP levels. Histopathologically, transmural intestinal damage were present in seven cases of SO and in six cases in the SMA occlusion group. CONCLUSIONS: Despite no significant difference between the two groups in terms of intestinal tissue damage, OFR-induced injury was higher in the strangulation obstruction group.     

Ischemia-reperfusion injury in transplantation: novel mechanisms and protective strategies

Solid organ transplantation remains the treatment of choice for many patients with end-stage organ failure. Because of the significant donor organ shortage, many transplant centers are using deceased donor allografts that are considered “marginal” and would have otherwise been discarded in previous years. In some instances, the use of these marginal grafts has resulted in inferior outcomes after transplantation. Ischemia-reperfusion injury (IRI) remains an important cause of organ dysfunction and allograft survival after transplantation. Despite many years of investigative research, there remains no standard treatment for IRI after solid organ transplantation. With the increased use of marginal allografts, there is a greater need to protect these organs from IRI, and researchers continue to seek novel mechanisms and strategies to minimize injury after transplantation. This review focuses on the recently identified mechanisms of IRI and novel protective strategies being studied to minimize IRI after transplantation.     

Ischemia-reperfusion injury of the human liver during hepatic resection

Haemorrhage during resection of the liver remains a significant threat to clinical outcome. Portal triad occlusion, with complete clamping of the hepatic inflow at the hepatoduodenal ligament, is a well-documented, safe, and useful means of alleviating this problem. Although this technique is effective in limiting blood loss, there is still controversy concerning the potential drawbacks of ischemia and subsequent reperfusion injury of the liver. This article highlights recent advances in our understanding of the clinical factors influencing ischemia-reperfusion injury of the liver, particularly in human patients. These factors include the cell components involved, the mechanisms that enable the human liver to tolerate long-term inflow occlusion, factors affecting clinical outcomes, and surgical and pharmacological techniques used to alleviate ischemia-reperfusion injury, including hypothermic hepatectomy.     

慢性脊髓压迫减压后的缺血再灌注损伤

目的探讨缺血再灌注损伤是否为慢性脊髓压迫症减压后不明脊髓功能丧失的致伤因素。方法成年新西兰白兔96只,随机分为A组（假手术组）,B组（缺血再灌注组）,C组（慢性压迫减压组）。于0h、0.5h、6h、12h、24h,48h各时间点每组分别取4只动物,检测MDA、CAT、SOD、GSH-Px表达水平;每组于0h及48h时各取4只动物取材行凋亡细胞计数。结果B组MDA、CAT、SOD、GSH-Px于0.5h、6h、12h、24h表达水平明显高于A组;C组MDA、CAT、SOD、GSH-Px于各时间点表达水平均明显高于A组,且C组组间各时间点表达水平无明显区别;C组0h及48h时TUNEL阳性细胞数量无明显差异。结论慢性脊髓压迫减压后减压局部并无明显缺血再灌注损伤标志,缺血再灌注并非减压后脊髓功能丧失的原因。     

Ischemia-reperfusion injury: processes in pathogenetic networks: a review

Ischemia-reperfusion injury is a complex phenomenon involving not only intracellular injury processes but also an injurious inflammatory response. Both the intracellular injury processes and the injurious events of the inflammatory response are interconnected in pathogenetic networks. Anoxic cell injury predominates in the ischemic phase. The decreased mitochondrial ATP generation impairs cellular ion homeostasis with activation of hydrolases and loss of selective permeability of cell membranes. Upon resupply of blood, the inflammatory response is initiated. Resident cells of the affected tissue, blood-derived cells, and noncellular elements such as the complement system are activated, and signalling and other molecules are formed at altered rates. Cell injury occurring in the reperfusion phase may either be a consequence of cellular alterations that were already initiated in the ischemic phase or may result from the inflammatory response. The intracellular injurious alterations are in part the same as those involved in anoxic cell injury. In addition, activation of intracellular signalling cascades and of apoptotic pathways may take place. Except for a large decrease in their rates, no significant difference exists between the injury processes during warm and cold ischemia as they become evident during ischemia itself. In contrast, the injury processes of the inflammatory response and of cell injury in the reperfusion phase significantly vary depending on pre-existent warm versus cold ischemia. Because of the netlike characteristics of the pathomechanisms, a multifactorial approach is required to provide protection against ischemia-reperfusion injury.     

Ischemia-reperfusion injury in rat skeletal muscle is attenuated by zinc aspartate

BACKGROUND: Oxygen-derived free radical-induced cell injury has been suggested to have a pivotal role in the etiology of ischemia-reperfusion injury. Thus, several lines of evidence indicate that antioxidant agents may be useful therapeutics in this condition. In this regard, the effect of zinc aspartate on ischemia-reperfusion injury was investigated in skeletal muscle. MATERIALS AND METHODS: Tourniquet ischemia-reperfusion injury method was applied to Sprague-Dawley rats. Experimental groups were as follows: 1) sham control, 2) rats received zinc aspartate, 3) rats received hind limb tourniquet operation (left side), and 4) rats received hind limb tourniquet operation and zinc aspartate. Viability of muscle was evaluated by triphenyltetrazolium chloride dye method by using a spectrophotometer. Malondialdehyde, superoxide dismutase, catalase, glutathione, and glutathione peroxidase were measured in muscle, heart, lung, and blood via a spectrophotometer. RESULTS: The viabilities of ischemic limbs, percentage of the contralateral control muscle, in group 1, 2, 3, and 4 were 114 +/- 12%, 87% +/- 5%, 20% +/- 2%, and 95 +/- 10%, respectively. In muscle, increased malondialdehyde and decreased superoxide dismutase, catalase, and glutathione levels in group 3 were normalized by zinc aspartate in both left and right limbs. While malondialdehyde levels in heart and blood increased in group 3, the levels of superoxide dismutase, catalase, glutathione, and glutathione peroxidase were lower in group 3 than those in group 1. All these alterations were prevented by zinc aspartate. Malondialdehyde level of lung in group 3 was significantly higher than group 1 and 2. However, this augmentation was halted by zinc aspartate. The decrease in superoxide dismutase levels in group 3 was statistically reversed by the administration of zinc aspartate. CONCLUSION: Zinc aspartate seems to be an effective treatment option against ischemia-reperfusion injury.