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.     

冬虫夏草对缺血再灌注肢体能量代谢和线粒体酶活性的影响

目的 观察冬虫草醇提取液对肢体缺血再灌注损伤的影响。方法 制作兔肢体缺血再灌注损伤动物模型，实验分对照组、再灌注组和治疗组。取骨骼肌测定三磷酸腺苷、二磷酸腺苷、一磷酸腺苷、磷酸肌酸含量和线粒体ATP酶活性。结果 再灌注组与对照组比较，骨骼肌能量代谢障碍及其线粒体ATP酶活性降低。使用冬虫夏草后，骨骼肌各项测定指标较再灌注组相比明显改善。结论 冬虫夏草对缺血再灌注损伤骨骼肌有保护作用。     

蝮蛇抗栓酶对骨骼肌缺血再灌注损伤保护的实验研究

目的探讨骨骼肌缺血再灌注损伤前后微循环变化及蝮蛇抗栓酶(Svate)的保护作用.方法 24只新西兰大白兔随机分成实验组和对照组,以气囊止血带造成兔左下肢缺血再灌注损伤模型.实验组分别在缺血前及再灌注前给予Svate静注,对照组给予等量生理盐水.用活体微循环显微镜观察兔缺血前及再灌注后骨骼肌微循环的变化并作血液流变学检测.结果骨骼肌缺血再灌注后对照组:全血粘度增高、血流缓慢、红细胞严重聚集、纤维蛋白原增加,大量白细胞附壁和白色微栓形成,无复流现象严重,微血管有渗出、渗血,骨骼肌组织损伤较重.随再灌注时间的推移,微循环障碍逐渐加重;实验组经Svate保护,血液流变学状况、微循环障碍明显好转,骨骼肌组织损伤较轻.结论①骨骼肌缺血再灌注后造成严重的微循环障碍和肌组织损伤;②Svate通过疏通微循环对骨骼肌缺血再灌注损伤起保护作用.     

缺血后处理和预处理对大鼠骨骼肌缺血-再灌注损伤的作用

目的 探讨缺血后处理( IPost)和缺血预处理(IPC)对大鼠骨骼肌缺血再灌注(IR)损伤的影响.方法 将40只大鼠随机分成缺血再灌注组(A组)、缺血后处理组(B组)、缺血预处理组(C组)、缺血预处理加缺血后处理组(D组)以及对照组(E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再灌注损伤,通过测定骨骼肌缺血4h、再灌注1h后血清丙二醛(MDA)和骨骼肌髓过氧化物酶(MPO),以及再灌注6h后骨骼肌的坏死程度来观察缺血后处理.缺血预处理及缺血预处理加缺血后处理对大鼠骨骼肌缺血再灌注损伤的影响.结果 B组、C组和D组再灌注1 h MDA和MPO水平以及再灌注6h骨骼肌坏死程度均低于A组(P＜ 0.05),但是高于E组(P＜0.05);B组和D组再灌注1 h MDA和MPO水平以及再灌注6h骨骼肌坏死程度基本相同(P＞0.05);B组和D组再灌注1 h MDA和MPO水平低于C组(P＜0.05),但再灌注6h骨骼肌坏死程度基本相同(P＞0.05).结论 应用缺血后处理和缺血预处理对大鼠骨骼肌缺血再灌注损伤有一定的保护效果,联合应用缺血后处理和缺血预处理,对骨骼肌缺血再灌注损伤的保护作用并没有明显增强.     

川芎嗪在骨骼肌缺血再灌注损伤中的作用

目的　探讨中药川芎嗪在骨骼肌缺血再灌注损伤中有无保护作用。方法　健康成年家兔14只 ,随机分对照组、实验组 ,每组 7只。应用家兔肢体缺血再灌注损伤动物模型 ,在恢复血流再灌注当时 ,实验组静脉输注川芎嗪注射液 ,对照组静脉输注 0 9%生理盐水。测定缺血前、缺血后、再灌注后血浆丙二醛 (MDA)、乳酸脱氢酶 (LDH)及超氧化物歧化酶 (SOD)的含量。制备骨骼肌标本进行光镜及透射电镜观察。结果　实验组在恢复血流并注射川芎嗪后 1小时 ,其血浆MDA、LDH的含量较对照组明显降低 (P <0 0 1) ,而SOD较对照组明显升高 (P <0 0 1)。光镜及电镜下观察可见实验组骨骼肌损害轻于对照组。结论　实验表明中药川芎嗪对骨骼肌缺血再灌注损伤有保护作用     

缺血预处理时间对大鼠骨骼肌缺血再灌注损伤保护作用的影响

目的探讨缺血预处理时间与骨骼肌缺血再灌注损伤保护作用之间的关系. 方法 36只大鼠随机分成 6组,制成切断患肢皮肤、肌肉和神经,仅保留股动静脉的动物模型.A组:直接缺血4 h再灌注;B、C、D和E组:分别缺血5、10、15和20 min,再灌注5、10、15和20 min,重复3次后缺血4 h再灌注;F组:制成仅保留股动静脉的左大腿组织块模型,未经过缺血处理.通过测定丙二醛(malondialdehyde, MDA)、骨骼肌水肿和坏死程度,观察不同预缺血时间对骨骼肌缺血再灌注损伤的保护作用. 结果对骨骼肌缺血后再灌注,预缺血5 min对骨骼肌即有保护作用,肌肉存活面积达82.47%;预缺血10和15 min肌肉存活面积增至最高,达89.03%和89.49%;预缺血20 min肌肉存活面积降至78.27%.预缺血5 min即可减轻骨骼肌水肿;预缺血10 min骨骼肌水肿程度最轻;预缺血15 min水肿程度又加重,预缺血20 min水肿程度继续加重.预缺血5、10和15 min MDA水平均降低,预缺血20 min MDA水平与单纯缺血再灌注组相同. 结论预缺血时间对大鼠骨骼肌缺血再灌注损伤的保护作用呈现先增强后减弱的趋势,以预缺血10 min保护作用最强.     

β-七叶皂甙钠对肢体缺血再灌注损伤的保护作用

目的：观察β－七叶皂甙钠对肢体缺血再灌注损伤的保护作用。方法：用兔造成肢体缺血再灌注损伤动物模型。实验分对照组、缺血再灌注组和β－七叶皂甙钠组。取血浆测定丙二醛、肌酸磷酸激酶、谷草转氨酶和乳酸脱氢酶合量。取骨骼肌标本测定丙二醛、髓过氧化酶活性、肌细胞线粒体钙含量和组织湿／干重比值。结果：缺血再灌注组与对照组比较,血浆和骨骼肌的各项生化指标显著增高（Ｐ〈０．０１）;使用β－七叶皂甙钠后,血浆及骨骼肌     

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。     

银杏叶提取液对缺血再灌注骨骼肌线粒体的保护作用

目的：观察银杏叶提取液对肢体缺血再灌注损伤的影响，方法：制作兔肢体缺血再灌注损伤动物模型，实验分对照组，再灌注组和治疗组，检测骨骼肌三磷酸腺苷（ATP）水平并观察线粒体超微结构的变化，测定线粒体丙二醛（MDA），还原型谷胱甘肽（GSH）和线粒体Ca含量。结果：再灌注组和对照组比较，以上各项指标差异显著（P＜0．01，P＜0．05），银杏叶提取液促进骨骼肌能量代谢，维持线粒体结构完整性，降低线粒体MDA含量，提高线粒体GSH水平并抑制线粒体Ca超载，治疗组各项测定指标较再灌注组比较明显改善（P＜0．05，P＜0．01），结论：银杏叶提取液对缺血再灌注骨骼肌线粒体有保护作用。     

灯盏花在肢体缺血/再灌注致远隔多器官损伤的预防作用

目的观察灯盏花在肢体缺血/再灌注致远隔多器官损伤的预防作用.方法实验共分三组(1)再灌注组夹闭大鼠双侧股动脉,阻断循环2h后再灌注5h,建立双下肢缺血/再灌注模型;(2)灯盏花组大鼠每日腹腔注射云南灯盏花注射液1ml,共7天,后按再灌注组方法制作模型;(3)对照组行假手术处理.观察大鼠下肢骨骼肌、远隔器官胃、肾、肺、肝及脑组织超微病理改变、红细胞超氧化物歧化酶(SOD)含量、组织丙二醛(MDA)含量、血清谷胱甘肽(GSH)含量,并观察灯盏花对远隔器官损伤的预防作用和对自由基的清除作用.结果再灌注组骨骼肌病变较单纯缺血时严重,远隔器官肝、肺、肾、胃及脑有弥漫性损伤;红细胞SOD及血清GSH较对照组显著下降(P＜0.05);肝、肺组织匀浆MDA含量显著增多(P＜0.05);灯盏花组病变较对照组明显改善.结论肢体缺血/再灌注不但使再灌注器官本身损伤加重,还可引起远隔多器官损伤;灯盏花作为强抗氧化剂,可明显减轻肢体缺血/再灌注所引起的远隔多器官损伤.     

The temporal relationship between endothelial cell dysfunction and skeletal muscle damage after ischemia and reperfusion.

Reperfusion-induced vascular endothelial cell dysfunction may exacerbate skeletal muscle damage after an ischemic insult. Although concurrent endothelial and skeletal muscle injury has been documented after ischemia and reperfusion, their temporal relationship has not been well characterized. An isolated rat hindlimb model was used to measure the effect of progressive ischemia and reperfusion on both endothelial cell function and skeletal muscle damage. Endothelial cell dysfunction as reflected by changes in permeability was measured by protein clearance techniques with use of albumin labeled with iodine 125 (125I-albumin). Skeletal muscle damage was assessed by tissue uptake of technetium 99m pyrophosphate (99mTc-pyrophosphate). The soleus muscle was used for evaluation of endothelial and skeletal muscle damage throughout the study. Significant increases in vascular permeability preceded skeletal muscle damage. The protein leak index increased after 60 minutes of ischemia and reperfusion (7.5 +/- 1.2 vs 4.1 +/- 0.9 control), whereas the muscle injury index did not change until 120 minutes of ischemia and 60 minutes of reperfusion (10.5 +/- 0.6 vs 4.5 +/- 0.5 control). Significant graded increases in both indexes were noted with longer intervals of ischemia. Electron microscopy revealed ultrastructural evidence of endothelial and skeletal muscle damage after 120 minutes of ischemia and 60 minutes of reperfusion but not after 60 minutes of ischemia and reperfusion. These studies indicate that microvascular injury precedes skeletal muscle damage after ischemia and reperfusion. This temporal relationship may have important implications in designing strategies to minimize ischemia-reperfusion injury.     

Polyadenosine diphosphate-ribose polymerase inhibition modulates skeletal muscle injury following ischemia reperfusion

HYPOTHESIS: Polyadenosine diphosphate-ribose polymerase (PARP) has been implicated as a mediator of inflammation and tissue necrosis in murine models of human stroke and myocardial infarction. This study was designed to determine whether PARP modulates skeletal muscle injury and cytokine-growth factor levels during ischemia-reperfusion. DESIGN: Prospective controlled animal study. SETTING: Medical school-affiliated university hospital. INTERVENTIONS: Mice were divided into 2 groups-treated (PJ) and untreated; all mice were subjected to unilateral hind limb tourniquet ischemia followed by 4 or 48 hours of reperfusion. In treated mice, PJ34, an ultrapotent-specific PARP inhibitor was given immediately before ischemia and prior to reperfusion. A group of PARP-1 knockout mice (PARP-/-) were also subjected to hind limb ischemia followed by 48 hours of reperfusion. MAIN OUTCOME MEASURES: After ischemia-reperfusion, muscle was harvested for measurement of edema, viability, cytokine, and vascular endothelial growth factor content. RESULTS: The PJ34-treated mice had increased skeletal muscle viability when compared with the untreated mice after 4 and 48 hours of reperfusion (P<.01). Viability between PARP-/- and PJ34-treated mice were similar at 48 hours of reperfusion (P>.05), and it exceeded that of untreated mice (P<.01). Tissue edema was unaltered by PARP inhibition. Tissue levels of cytokine were only different (P<.05) in PJ34-treated vs untreated mice at 48 hours of reperfusion. Vascular endothelial growth factor levels in PJ34-treated mice were markedly reduced when compared with untreated mice only after 4 hours of reperfusion (P<.01), and in PARP-/- mice (P<.01) at 48 hours of reperfusion. CONCLUSIONS: Polyadenosine diphosphate-ribose polymerase modulates skeletal muscle viability, cytokine and vascular endothelial growth factor synthesis during reperfusion. Polyadenosine diphosphate-ribose polymerase inhibition may represent a novel method to modulate skeletal muscle ischemia-reperfusion injury.     

Iloprost infusion decreases skeletal muscle ischemia-reperfusion injury.

Iloprost (a long-acting prostacyclin analog) has been demonstrated to decrease cardiac muscle infarct size after ischemia-reperfusion injury. We investigated the ability of iloprost to decrease skeletal muscle injury and platelet sequestration after ischemia-reperfusion injury in a canine bilateral isolated gracilis muscle model. Anesthesized animals (n = 13) were subjected to 6 hours of gracilis muscle ischemia and 1 hour of reperfusion. Fifteen minutes before muscle reperfusion, the animals were infused with radium 111-labeled autogenous platelets. Experimental animals (n = 7) received a continuous preischemic intravenous infusion of iloprost (0.45 microgram/kg/hr) and two 0.45 microgram/kg intravenous injections of iloprost (10 minutes before the ischemic interval and 10 minutes before reperfusion). Muscle injury was measured with triphenyltetrazolium chloride histochemical staining. Platelet sequestration within ischemic muscle specimens was determined by measuring indium 111 activity in a gamma counter. Iloprost infusion decreased muscle infarct size from 57.0% +/- 12.6% in control animals to 15.8% +/- 4.4% in experimental animals (p less than 0.05). Platelet uptake in experimental and control muscle was 1.2 +/- 0.21 x 10(7) and 2.17 +/- 0.48 x 10(7) platelets/gm ischemic muscle, respectively (p = 0.1). Although platelet sequestration was not altered significantly in this experiment, a reduction in skeletal muscle injury was confirmed. Further investigation on the mechanisms of action of iloprost in chronic and acute skeletal muscle ischemia is warranted.     

Permeability changes following ischemia-reperfusion injury in the rabbit hindlimb.

Changes in permeability following ischemia-reperfusion injury were assessed in the intact rabbit hindlimb by measuring the transvascular clearance of 125I-labeled rabbit serum albumin. Ischemia was induced for periods of 1 or 2 hours by use of a pneumatic tourniquet inflated to 300 mmHg. Following ischemia, the limb was reperfused for 1, 2, or 3 hours. The albumin clearance in the gastrocnemius muscle of control rabbits was 5.1 +/- 0.7 (mean +/- SEM) microliters/hr/g dry weight. Following 1 hour of ischemia and reperfusion, muscle albumin clearance rose to 71.4 +/- 26 microliters/hr/g dry weight which was not significantly different from those animals that underwent 2 hours of ischemia. Muscle albumin clearance continued to be elevated following 2 hours of reperfusion; however, it returned toward control levels after 3 hours of reperfusion. These data suggest there is a transient increase in albumin permeability following ischemia-reperfusion injury in skeletal muscle.     

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.     

Effect of different periods of hyperbaric oxygen on ischemia-reperfusion injury of rat skeletal muscle

The effect of hyperbaric oxygen (HBO) on ischemia-reperfusion injury of skeletal muscle, applied during different periods, was studied in 56 male rats. Animals were subjected to 6-h ischemia by a tourniquet over the major femoral trocanter and 4 (A) or 24 (B) h of reperfusion. HBO was carried out during 1 h in an acrylic chamber at a pressure of 2.0 ATA (100% oxygen): in the last 60 min of ischemia (II), after ischemia, during 1-h reperfusion time (III), and during the last hour of ischemia plus 1-h reperfusion (IV). Group I was the control group. After 4- or 24-h reperfusion, samples of the soleus muscle were stained by H&E and analyzed immunohistochemically. No interstitial hemorrhage, neutrophil infiltrate, or cellular necrosis were induced by HBO. The apoptosis index did not differ among the groups. HBO reduced morphologic alterations and promoted better results when administered in the ischemia plus reperfusion period (GIV).     

左旋精氨酸对再灌注期大鼠提睾肌微循环的作用

目的 探讨再灌注期肌瓣微循环的变化及其与NO的关系。方法 以体重180－220g雄性SD大鼠,制成大鼠提睾肌缺血再灌注模型（热缺血5h,再灌注2h）,应用电视显微影像系统,观察缺血再灌注期肌瓣微循环的变化。结果 ①再灌注期左旋精氨酸（L－arg)治疗组微动脉复流率较对照组明显增高（P＜0．01）,对照组于再灌注30min微动脉复流率最低,仅为53％。②再灌注期L－arg能使复流之微动脉A1、A2的血管收缩幅度明显减小（P＜0．05）,血管流速明显加快,毛细血管的灌流密度显著增加。③再灌注期微静脉内皮细胞受损,静脉回流障碍,局部形成一种“只灌不流”的病理现象,使肌瓣组织出现大片明显的漏出性出血。结论 NO生成剂能够扩张微动脉,疏通肌瓣的微循环,改善组织的灌 流;再灌注期微静脉回流障碍可能是造成组织损伤的重要因素。