阻断CD18介导的白细胞粘附对岛状皮瓣成活的影响

目的研究白细胞及白细胞粘附在缺血再灌注损伤中的作用。方法应用大鼠腹部岛状皮瓣模型，检测了皮瓣髓过氧化酶（ＭＰＯ）和丙二醛（ＭＤＡ）含量，观察了皮瓣的成活情况。结果与正常时相比，缺血８小时及再灌注１小时皮瓣ＭＰＯ和ＭＤＡ水平明显增高，而以抗ＣＤ１８单抗阻断白细胞粘附可明显减轻这种变化，并有效地提高皮瓣的存活面积。结论ＣＤ１８介导的白细胞粘附参与了皮瓣再灌注损伤过程，抗ＣＤ１８单抗阻断白细胞粘附能减轻白细胞介导的组织损伤，并对岛状皮瓣具有保护作用。     

阻断CD18介导的白细胞粘附对岛状皮瓣成活的影响

研究白细胞白细胞粘附在缺血再灌注损伤中的作用。方法，应用大鼠腹部岛状皮瓣模型，检测了皮瓣过氧化酶和丙二醛含量，观察了皮瓣的成活情况。结论ＣＤ１８介导 白细胞粘附参与了皮瓣再灌注损伤过程，抗ＣＤ１８单抗阻断白细胞附能减轻白细胞介导的组织损伤，并对岛状皮瓣具有保护作用。     

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。     

外源性锌对缺血再灌注损伤皮瓣超微结构的影响

目的:观察外源性锌对缺血再灌注(ischemia-reperfusionIR)损伤皮瓣的保护作用。方法:48只大鼠随机分为对照组(n=16)、缺血再灌注组即IR组(n=16)和补锌缺血再灌注组即补锌-IR组(n=16)。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。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,并观察皮瓣成活率。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%,MPO活性分别较IR组降低17.9%、21.4%。补锌-IR组皮瓣的超微结构改变较IR组明显减轻,皮瓣成活率较IR组升高27.2%。结论:外源性锌能显著减轻缺血再灌注损伤皮瓣中组织细胞超微结构的病理改变,对皮瓣缺血再灌注损伤产生一定的保护作用。     

热应激预处理对皮瓣缺血再灌注损伤的影响及机制

目的探索减轻皮瓣缺血再灌注损伤的有效措施。方法采用大鼠腹部岛状皮瓣,制作活体原位热缺血模型,观察热缺血再灌注后皮瓣的成活率、皮瓣组织形态学改变,检测皮瓣超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、HSP_(70)表达。结果缺血8h 后再灌注,实验组皮瓣存活率明显高于对照组;与对照组相比,实验组皮瓣组织中 SOD 活性较高而 MDA 水平较低;电镜显示,实验组皮瓣毛细血管内膜较完整,细胞肿胀轻,线粒体结构较稳定。结论热应激预处理,能减轻缺血再灌注对皮瓣的损伤,对缺血再灌注皮瓣具有保护作用,其机制可能与热应激预处理抗自由基损害作用及维护细胞膜结构稳定有关。     

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     

缺血再灌注对大鼠岛状浅筋膜瓣超微结构的损伤及Verpamil的作用观察

探讨Ｖｅｒｐａｍｉｌ对大鼠皮瓣超微结构缺血再灌注损伤的保护作用。建立ＳＤ大鼠腹壁浅筋膜岛状皮瓣模型，缺血５小时再灌注２０分钟，在电子显微镜下观察其超微结构的变化，并用Ｖｅｒｐａｍｉｌ作保护性对比。损伤以细胞膜和线粒体为主，Ｖｅｒｐａｍｉｌ组的损伤明显减轻。实验结果提示，Ｖｅｒｐａｍｉｌ对皮瓣的超微结构具有保护作用。     

去白细胞血复苏失血性休克家兔对多器官再灌注损伤的影响

中性粒细胞(PMNs)介导组织损伤(NMTI)在组织器官缺血再灌注损伤中的作用越来越受到重视。通过过滤、应用药物或抗中性白细胞血清等方法消耗白细胞,可减轻缺血再灌注损伤。目前应用去白细胞血的方法复苏失血性休克对多器官再灌注损伤影响尚无定论。本研究拟通过观察回输去白细胞血和全血对失血性休克大鼠复苏后重要器官组织(心、肺、肝、肾、肠)髓过氧化物酶(MPO)、黄嘌呤氧化酶(XOD)、丙二醛(MDA)、活性氧(OH°)的影响,探讨去白细胞血复苏失血性休克对多器官再灌注损伤的影响。     

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。     

热应激预处理对皮瓣缺血再灌注损伤的影响及机制

目的　探索减轻皮瓣缺血再灌注损伤的有效措施。方法　采用大鼠腹部岛状皮瓣,制作活体原位热缺血模型,观察热缺血再灌注后皮瓣的成活率、皮瓣组织形态学改变,检测皮瓣超氧化物歧化酶（ Ｓ Ｏ Ｄ） 活性、丙二醛（ Ｍ Ｄ Ａ） 含量、 Ｈ Ｓ Ｐ７ ０ 表达。结果　缺血８ｈ 后再灌注,实验组皮瓣存活率明显高于对照组;与对照组相比,实验组皮瓣组织中 Ｓ Ｏ Ｄ 活性较高而 Ｍ Ｄ Ａ 水平较低;电镜显示,实验组皮瓣毛细血管内膜较完整,细胞肿胀轻,线粒体结构较稳定。结论　热应激预处理,能减轻缺血再灌注对皮瓣的损伤,对缺血再灌注皮瓣具有保护作用,其机制可能与热应激预处理抗自由基损害作用及维护细胞膜结构稳定有关。     

Effect of superoxide dismutase for improvement of survival of ischemic reperfused island skin flap]

Using a rat model, we evaluated the effect of SOD on the survival of ischemic reperfused island skin flaps. In experiment 1, the oxygen free radical concentration in the flaps was measured by the technique of ESR. The results showed that the oxygen free radical concentration in ischemic reperfused flaps was significantly higher than in the corresponding control flaps (P less than 0.001). In experiment 2, the flaps were perfused with SOD (2000 U in 1 ml saline) before reperfusion after 8 hours of ischemia. Seven days after operation, the area of flap survived in the test group was significantly larger than in the control group (P less than 0.0005). The obtained data demonstrated that the generation of oxygen free radical increases with time during ischemia reperfusion in island skin flap and the role of oxygen free radical in tissue injury following ischemia and reperfusion. The use of SOD can enhance the survival of ischemic island skin flap.     

Prevention of reperfusion injury of an ischemic flap: an experimental study]

Oxygen-derived free radicals are important mediators of tissue injury in experimental island skin flaps that have been subjected to prolonged ischemia (vascular occlusion) followed by reperfusion. In this study, the role of oxygen free radical scavenger, SOD, and a herb, salvia miltiorrhiza, in the protection of cellular damages during total ischemia and reperfusion was study in the epigastric island skin flaps in experimental rats with electron microscopy and the assessment of survival of the flaps. Control flaps subjected to 10 hours of total vascular occlusion showed a high incidence of necrosis when followed for 7 days following release of the vascular occlusion. Treatment with superoxide dismutase and salvia miltiorrhiza prior to the onset of reperfusion significantly enhanced island flap survival to 72.5% (P < 0.001) and to 64.2% (P < 0.05), respectively. The conclusions are: 1. Reperfusion for 10 hours following ischemia for 8 hours in the epigastric island flaps of the rats greatly exaggerated the original injury. 2. SOD and salvia miltiorrhiza may protect the flaps from such injury considerably and enhanced flap survival.     

热应激预处理对皮瓣缺血再灌注损伤的影响及机制

OBJECTIVE: This study was to develop a new method that can lessen ischemia reperfusion injury and improve the survival of the island flap. METHOD: A right lower abdominal island flap was created in the SD rat according to the protocol of Harashina. Animals were divided into 2 groups (heat-shock pretreatment and control groups). The island flap viability and electronic microscopical appearance of flap tissue were evaluated following ischemia reperfusion injury. In order to explore the mechanism of this phenomenon, we examined the contents of HSP70 and measured the levels of SOD and MDA of the flap at various times. RESULTS: Compared with the control group, SOD activities of the flap were higher, and MDA content was lower. Survival rate of the island flap with heat-shock pretreatment was significantly increased (P < 0.01). CONCLUSION: The heat-shock pretreatment can lessen ischemia reperfusion injury and improve the survival of the island flap. It is suggested that the mechanism be related to following aspects: 1. The heat-shock pretreatment maintains stability of cell's function and structure. 2. It may increase the ability to catabolize free radicals by antioxidative enzymes.     

The effect of a free-radical scavenger, N-2-mercaptopropionylglycine, on the survival of skin flaps

Oxygen free radicals may have an important role in tissue injury, which occurs on reperfusion of previously ischemic skin flaps. Therefore, therapy directed against the toxic effects of reactive oxygen species may protect skin flaps from ischemia/reperfusion injury. Various scavengers of oxygen free radicals have previously been reported to be effective in ameliorating ischemia/reperfusion injury. In the present study, N-2-mercaptopropionylglycine (MPG), a free-radical scavenger, was evaluated for its effectiveness in limiting the extent of necrosis resulting from ischemia/reperfusion injury in rat skin. Island skin flaps were elevated in the abdomen and groin based on an inferior epigastric neurovascular pedicle. The venous drainage from the flap was occluded for 7 hours, and reperfusion was established. The majority of flaps in the control group exhibited complete necrosis on Day 7 postoperatively. Treatment with systemic MPG (20 mg/kg of body weight) significantly improved flap survival from 22 to 71% (p less than 0.01) when administered at the time of reperfusion. However, MPG administered 1 hour after reperfusion did not influence the survival of the flaps. The results suggest that MPG may exert its beneficial effects on flap survival by scavenging oxygen free radicals formed at the time of reperfusion following prolonged ischemia.     

Tadalafil significantly reduces ischemia reperfusion injury in skin island flaps

Introduction:

Numerous pharmacological agents have been used to enhance the viability of flaps. Ischemia reperfusion (I/R) injury is an unwanted, sometimes devastating complication in reconstructive microsurgery. Tadalafil, a specific inhibitor of phosphodiesterase type 5 is mainly used for erectile dysfunction, and acts on vascular smooth muscles, platelets and leukocytes. Herein, the protective and therapeutical effect of tadalafil in I/R injury in rat skin flap model is evaluated.

Materials and Methods:

Sixty epigastric island flaps were used to create I/R model in 60 Wistar rats (non-ischemic group, ischemic group, medication group). Biochemical markers including total nitrite, malondialdehyde (MDA) and myeloperoxidase (MPO) were analysed. Necrosis rates were calculated and histopathologic evaluation was carried out.

Results:

MDA, MPO and total nitrite values were found elevated in the ischemic group, however there was an evident drop in the medication group. Histological results revealed that early inflammatory findings (oedema, neutrophil infiltration, necrosis rate) were observed lower with tadalafil administration. Moreover, statistical significance (P < 0.05) was recorded.

Conclusions:

We conclude that tadalafil has beneficial effects on epigastric island flaps against I/R injury.KEY WORDS: Free radicals, ischemia, island flap, reperfusion injury, tadalafil     

阿魏酸钠对移植皮瓣缺血再灌注损伤保护的实验研究

目的：通过建立大鼠皮瓣移植损伤的动物模型,观察阿魏酸钠对皮瓣存活率的影响。方法：利用H＆E染色分析皮瓣的损伤程度,利用免疫组化检测皮瓣组织中COX-2及HO-1的表达水平,利用ELISA法检测皮瓣组织中MPO、MDA、NO的含量以及外周血中TNF-α的表达水平。结果：在移植皮瓣缺血再灌注损伤模型中,相比于生理盐水处理组,阿魏酸钠处理可显著提高皮瓣的存活率,同时上调皮瓣组织中HO-1的表达水平,抑制COX-2通路的活化。在阿魏酸钠的作用下,皮瓣组织的MPO、MDA的含量明显下降,同时NO的合成增加,阿魏酸钠可显著抑制外周血中TNF-α的表达水平。结论：阿魏酸钠对移植皮瓣缺血再灌注损伤具有明显的保护作用,其作用机制与减少炎症反应,抑制氧化应激损伤密切相关。     

缺血-再灌注损伤对扩张皮瓣转移术后的影响

目的：探讨缺血-再灌注损伤对扩张皮瓣转移术后的影响。方法：以实验兔每侧腹壁浅动脉为中线,于两侧腹部植入50ml软组织扩张器各一只,术后定期注水扩张至80ml为止。分别于扩张皮瓣转移前、转移后1h、24h、72h检测腹壁浅动脉血流速度,切取皮瓣远端组织在200倍光镜下进行白细胞计数,检测皮瓣组织中丙二醛（MDA）、髓过氧化物酶（MPO）含量。结果：扩张皮瓣转移前腹壁浅动脉的血流速度为（13.2±0.78）cm/s,光镜下白细胞计数为（8.33±2.61）个,皮瓣组织内MDA含量为（1.72±0.57）nmol/mgprot,MPO含量为（126.50±20.70）U/g。皮瓣转移术后1h血流速度为（6.22±0.93）cm/s,白细胞计数为（19.08±4.94）个,MDA含量为（4.05±0.67）nmol/mgprot,MPO含量为（349.42±27.27）U/g。皮瓣转移术后24h血流速度为（8.37±0.56）cm/s,白细胞计数为（60.17±6.24）个,MDA含量为（6.68±0.73）nmol/mgprot,MPO含量为（558.08±26.99）U/g。皮瓣转移术后72h血流速度为（17.36±1.06）cm/s,白细胞计数为（34.00±3.79）个,MDA含量为（2.51±0.41）nmol/mgprot,MPO含量为（215.92±25.97）U/g。结论：在扩张皮瓣转移术后发生缺血-再灌注的过程中,皮瓣组织发生再灌注损伤。     

Improved survival in free skin flap transfers in rats

We have demonstrated previously that oxygen-derived free radicals are important mediators of tissue injury in experimental island skin flaps that have been subjected to prolonged ischemia (vascular occlusion) followed by reperfusion. In this study the role of oxygen free radicals in ischemia/reperfusion injury has been investigated in free flap transfers. Groin skin flaps were harvested, stored at room temperature for 21 to 24 hours, and transplanted to the contralateral groin. These free flap transfers normally exhibit a high incidence of complete necrosis. Treatment before the onset of reperfusion with a single dose of superoxide dismutase (SOD), a scavenger of superoxide radicals, increased the survival rate of these skin flaps from 38% in the control group to 76% (p less than 0.025). Tissue levels of SOD were measured before ischemia, after ischemia but before reperfusion, and 30 minutes after reperfusion: untreated flap tissues, which were destined to undergo necrosis, exhibited a significant decrease in SOD activity after reperfusion, whereas SOD-treated flap tissues, destined to survive, demonstrated increased enzyme activity. High levels of tissue SOD activity thus appeared to be associated with improved flap survival. The results have significant clinical implications with regard to organ preservation and transplantation.