缺血预处理对骨骼肌缺血再灌注损伤的保护机制及其与腺苷关系研究

目的 :探讨骨骼肌缺血预处理保护作用机制及其腺苷的关系。方法 :采用兔右后肢缺血模型 ,将 2 8只兔随机分为 4组 (n =7) ,对照组 :持续缺血 4h ,再灌注 1h ;预处理组 :缺血 5min ,再灌注 5min ,重复 3次后 ,持续缺血 4h再灌注1h。腺苷治疗组 :于缺血再灌注前经股动脉注入 0 5mg腺苷。腺苷受体拮抗剂 8-PT处理组 :在 3次循环IPC处理前 ,经股动脉注入 3 0mg 8-PT ,再缺血 4h ,再灌注 1h。通过高效液相色谱法测定处理前、缺血 4h ,再灌注 10min、3 0min及6 0min时血浆腺苷浓度变化。通过血浆CPK、MDA及骨骼肌99mTcMDP吸收量的测定判断骨骼肌损伤程度。结果 :预处理组、腺苷组及 8-PT组 ,在缺血 4h和再灌注 1h期间血浆腺苷浓度明显升高 (P <0 0 1) ,再灌注 10min时达到高峰 ,并随再灌注时间延长而逐渐降低。与对照组相比 ,预处理组和腺苷组血浆CPK、MDA及骨骼肌99mTcMDP吸收量显著降低 (P <0 0 1)。结论 :腺苷参与了缺血预处理对骨骼肌的保护作用 ,腺苷受体拮抗可阻断缺血预处理对骨骼肌的保护作用。腺苷释放和腺苷受体激活在骨骼肌缺血预处理中起重要作用。     

血液稀释和川芎嗪对兔缺血-再灌注损伤心肌内酶及超微结构的影响

目的 观察6%羟乙基淀粉130/0.4(HES 130/0.4)等容血液稀释和川芎嗪对兔心肌缺血-再灌注损伤中心肌磷酸肌酸激酶(CPK)、乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量及超微结构的影响.方法 32只家兔随机均分为四组:血液稀释组(H组)、川芎嗪组(L组)、血液稀释+川芎嗪组(HL组)及对照组(C组).观察在急性心肌缺血45 min、再灌注180min后心肌组织中CPK、LDH、SOD活性及MDA含量,并以透射电镜观察心肌超微结构的改变.结果 与同组非缺血区相比,四组缺血区心肌组织CPK、LDH、SoD活性均明显降低,MDA含量明显升高(P<0.05或P<0.01).与C组缺血区比较,H组缺血区心肌组织CPK、LDH、SOD活性均升高(P<0.05);L组缺血区心肌组织CPK、SOD活性升高,MDA含量降低(P<0.05);HL组缺血区心肌组织CPK、LDH、SOD活性均明显升高(P<0.01),MDA含量降低(P<0.05),且CPK活性高于L组缺血区(P<0.05).心肌细胞超微结构可见C组细胞结构破坏严重,H、L组细胞结构破坏均较C组轻,HL组细胞结构基本接近正常.结论 6%HES 130/0.4等容血液稀释和川芎嗪对心肌缺血-再灌注损伤均有保护作用,二者合用保护作用更为显著.     

等容血液稀释和川芎嗪对兔心肌缺血再灌注损伤的保护作用

目的 观察6％羟乙基淀粉(HAES)等客血液稀释和川芎嗪注射液对兔心肌缺血再灌注损伤的保护作用。方法 32只家兔随机分为4组(n=8):组Ⅰ(对照组);组Ⅱ(稀释组);组Ⅲ(川芎嗪组);组Ⅳ(稀释+川芎嗪组),观察在急性心肌缺血45min和再灌注180min状态下血浆及心肌组织中磷酸肌酸激酶(CPK)及乳酸脱氢酶(LDH)活性的变化,并以透射电镜观察心肌超微结构改变。结果缺血及再灌后,组Ⅰ血浆CPK、LDH活性进行性升高(P<0.05,P<0.01),缺血区心肌组织CPK、LDH活性明显降低(P<0.01)。再灌后与组Ⅰ相比,组Ⅱ、Ⅲ血浆LDH活性均降低(P<0.05),组Ⅱ缺血区心肌组织CPK、LDH活性均升高(P<0.05),组Ⅲ缺血区心肌组织CPK活性升高(P<0.05),组Ⅳ血浆CPK、LDH活性均降低(P<0.05,P<0.01),且LDH活性低于同期组Ⅱ(P<0.05),缺血区心肌组织CPK、LDH活性均显著升高(P<0.01),且CPK活性高于组Ⅲ缺血区(P<0.05)。心肌细胞超微结构可见组Ⅰ细胞结构破坏严重,组Ⅱ、Ⅲ结构破坏均较组Ⅰ轻,组Ⅳ结构基本接近正常。结论 6％HAES等容血液稀释和川芎嗪对心肌缺血再灌注损伤均有保护作用,二者合用保护作用更为显著。     

烟碱预处理对大鼠心肌缺血-再灌注损伤的保护作用

目的 探讨烟碱预处理对大鼠心肌缺血-再灌注损伤的保护作用及其可能机制.方法 30只健康雄性Sprague-Dawlay大鼠,体重200～250g,随机均分为缺血-再灌组(I-R组)、烟碱预处理组(N组)、假手术组(Sham组).测定三组血浆肌酸激酶同工酶(CK-MB)活性、丙二醛(MDA)含量和超氧化物岐化酶(SOD)活性,心肌组织中髓过氧化物酶(MPO)活性,电镜下观察缺血区心肌超微结构变化.结果 与Sham组比较,I-R组血浆CK-MB活性、MDA含量及心肌组织MPO活性均升高、血浆SOD活性降低(P<0.05或P<0.01);与I-R组比较,N组血浆CK-MB活性、MDA含量及心肌组织MPO活性均降低,血浆SOD活性升高(P<0.05或P<0.01),心肌病理学损伤减轻.结论 烟碱预处理可减轻大鼠心肌缺血-再灌注损伤,其机制可能与减少氧自由基生成、增强心肌抗氧化能力有关.     

缺血预处理对兔骨骼肌再灌注损伤延迟保护作用的实验研究

目的探讨缺血预处理对兔骨骼肌再灌注损伤是否存在早期、延迟保护作用及保护程度。方法选择30只新西兰大白兔随机等分为对照组、早期保护组(EP)和延迟保护组(DP)。对照组直接用气囊止血带阻断兔后肢血流4h,造成骨骼肌缺血再灌注损伤模型。EP和DP组先进行缺血预处理,分别在预处理后立即和24h后用气囊止血带阻断兔后肢血流4h造成缺血再灌注模型。测定再灌注期血清中肌酸磷酸激酶(CPK)、天门冬酰胺氨基转移酶(AST)和超氧化物歧化酶(SOD)含量,光、电镜下观察骨骼肌结构变化。结果再灌注后1、2、4、8h,EP与DP组血清中CPK和AST的含量均明显低于对照组(P<0.01);SOD含量明显高于对照组(P<0.01),而EP与DP组之间差异无显著性意义(P>0.05)。骨骼肌线粒体空泡变性和肌原纤维溶解均延迟出现,其病变程度明显轻于对照组。结论缺血预处理不仅存在早期、延迟保护作用,且均能提高骨骼肌对长时间缺血的耐受能力,减轻骨骼肌缺血再灌注损伤程度,这两种保护作用的程度无明显差异。     

缺血后处理对减轻骨骼肌缺血再灌注损伤作用的实验研究

目的：研究缺血后处理对鼠骨骼肌缺血再灌注损伤的保护影响,组织中凋亡和胀亡的存在情况。方法将54只SD大鼠随机分为空白对照组、缺血再灌注组、缺血后处理组,持续缺血4 h,再灌注6 h,24 h,48 h。检测血浆乳酸脱氢酶（LDH）、肌酸磷酸激酶（CPK）活性、肌肉内丙二醛（MDA）含量及总超氧化物歧化酶（SOD）活性,进行组织学、免疫组化、超微结构分析。结果相比缺血再灌注组,后处理组在再灌注6 h时,只SOD活性明显升高,而再灌注24 h,48 h时,在MDA含量下降、SOD活性升高、W/D值下降、组织学改变范围及免疫组化阳性范围方面,均较缺血再灌注组有明显差异。结论再灌注开始时应用后处理对于缺血再灌注损伤有明显的保护作用,主要体现在再灌注的稍后期阶段（再灌注24 h,48 h）。缺血再灌注过程中,凋亡和胀亡是并存的。     

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     

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.     

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。     

三甲氧苄嗪对大鼠脊髓缺血-再灌注损伤的保护作用

目的评价三甲氧苄嗪(trimetazidine)对大鼠脊髓缺血-再灌注损伤的保护作用,并探讨其作用机制. 方法 45只SD大鼠采用随机数字表法分为3组,每组15只.建立大鼠脊髓缺血损伤模型,假手术组:行开腹手术,不阻断主动脉;对照组:剖腹后阻断主动脉20分钟;三甲氧苄嗪组:于主动脉阻断前10分钟静脉内注射三甲氧苄嗪(3mg/kg),其余处理与对照组相同.测定血浆丙二醛(MDA)含量,术后48小时按Tarlov评分标准评价动物后肢神经功能,取脊髓进行含水量、MDA含量测定及组织病理学检查.结果三甲氧苄嗪组血浆MDA含量明显低于对照组(P<0.05),动物后肢神经功能评分明显优于对照组(P<0.01),脊髓含水量、MDA含量明显低于对照组(P<0.01);三甲氧苄嗪组在光学显微镜下脊髓病理改变轻微,而对照组脊髓损伤较重,两组病理评分差别有显著性意义(P<0.01).结论三甲氧苄嗪对大鼠脊髓缺血-再灌注损伤具有明显的保护作用.     

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     

扩散张量成像诊断兔急性缺血性骨骼肌溶解

目的探讨DTI在诊断兔急性缺血性骨骼肌溶解中的价值。方法将26只新西兰大白兔一侧后肢供血动脉及侧支血管结扎,建立后肢急性缺血模型(骨骼肌溶解组);以对侧作为对照组。于术后8h对两侧后肢进行T2WI及DTI,测量外侧肌肉ADC值及FA值,留取相应部位肌肉组织进行透射电镜检查。结果于26只兔均成功建立后肢骨骼肌缺血模型。血管结扎后8h骨骼肌溶解组肌肉T2WI信号增高;ADC值为(1.26±0.25)×10-9 m2/s,高于对照组[(0.98±0.38)×10-9 m2/s,P<0.05],FA值为0.16±0.03,低于对照组(0.28±0.05,P<0.05);透射电镜示骨骼肌溶解组骨骼肌出现溶解。结论 DTI可诊断骨骼肌缺血后坏死和溶解,具有重要临床应用价值。     

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     

Alpha-tocopherol (Vitamin E) and iloprost attenuate reperfusion injury in skeletal muscle ischemia/reperfusion injury

BACKGROUND: The aim of this study was to clarify the role of a-tocopherol (vitamin E) and iloprost on skeletal muscle ischemia/reperfusion injury. METHODS: Setting: animal research laboratory of a university hospital. Experimental design: the iliac arteries of the 24 adult Sprague-Dawley rats were clamped and 4 hours of ischemia followed by 1 hour of reperfusion was applied. In an attempt to decrease reperfusion injury, the rats were given either a-tocopherol (n=8), iloprost (n=6) and 8 rats were given normal saline and served as control group (n=8). Measures: blood pH, pO2, pCO2, HCO3, Na, K, creatine kinase (CPK), lactate dehydrogenase (LDH) values were determined at the end of the reperfusion period. Malondialdehyde (MDA), a product of lipid peroxidation, was measured in blood, muscle and lung as an indicator of free radicals. RESULTS: Blood pO2 and HCO3 levels were significantly high (p<0.05); CPK, LDH and MDA levels were significantly low (p<0.05) in both a-tocopherol and iloprost groups when compared to the control group. Similarly, the MDA levels in the gastrocnemius muscle were significantly low in both treatment groups when compared to the controls (p<0.05). There was no significant difference between groups in other parameters. CONCLUSIONS: The results suggest that, both a-tocopherol and iloprost are useful for attenuating oxidative muscle damage occurring after a period of ischemia/ reperfusion.     

Attenuation of skeletal muscle ischemia/reperfusion injury by inhibition of tumor necrosis factor

Purpose: Tumor necrosis factor α (TNF-α) has been shown to play a role in pulmonary injury after lower-extremity ischemia/reperfusion (I/R). However, its role in direct skeletal muscle injury is poorly understood. The hypothesis that endogenous TNF production contributes to skeletal muscle injury after hindlimb I/R in rats was tested. Methods: Juvenile male Sprague-Dawley rats underwent 4 hours of bilateral hindlimb ischemia and 4 hours of reperfusion (IR) or sham operation (SHAM). A subset was treated with a soluble TNF receptor I construct (STNFRI, 10 mg/kg) 1 hour before ischemia (PRE) or at reperfusion (POST). Direct skeletal muscle injury (SMII) and muscle endothelial capillary permeability (MPI) were quantified by means of Tc⁹⁹ pyrophosphate and I¹²⁵ albumin uptake. Pulmonary neutrophil infiltration and hepatocellular injury were assessed by means of myeloperoxidase content (MPO) and aspartate aminotransferase (AST) concentrations, respectively. Serum TNF bioactivity was measured with the WEHI bioassay. Results: Hindlimb I/R (IR vs SHAM) resulted in a significant (P < .05) increase in the SMII (0.52 ± 0.06 vs 0.07 ± 0.01) and MPI (0.35 ± .04 vs 0.06 ± 0.01). Pretreatment with STNFRI (PRE vs IR) significantly ameliorated both SMII (0.30 ± 0.05 vs 0.52 ± 0.06) and MPI (0.23 ± 0.02 vs 0.35 ± 0.04), whereas treatment at reperfusion (POST vs IR) had no effect. Hindlimb I/R (IR vs SHAM) resulted in both significant pulmonary neutrophil infiltration (MPO 16.4 ± 1.06 U/g vs 11.3 ± 1.4 U/g) and hepatocellular injury (AST 286 ± 45 U/mL vs 108 ± 30 U/mL), but neither was inhibited by pretreatment with STNFRI before ischemia. Detectable levels of TNF were measured during ischemia in a significantly higher percentage of the IR group compared with SHAM (9 of 12 vs 3 of 12), and the maximal TNF values were also significantly greater (51.1 ± 12.6 pg/mL vs 5.5 ± 2.9 pg/mL). No TNF was detected in any treatment group during reperfusion nor after administration of the STNFRI. Conclusion: Acute hindlimb IR initiates a systemic TNF response during the ischemic period that is partly responsible for the associated skeletal muscle injury. (J Vasc Surg 1999;29:370-6.)     

缺血预处理减轻骨骼肌缺血再灌注损伤

目的 观察缺血预处理对骨骼肌缺血再灌注损伤的保护作用。方法 选择２４只健康兔,随机等分为实验组和对照组。实验组先进行缺血预处理,再持续阻断后肢血流４ｈ;对照组直接阻断后肢血流４ｈ,制作骨骼肌缺血再灌注损伤模型。测定再灌注期血清中肌酸磷酸激酶（ＣＰＫ）和天门冬氨酸氨基转移酶（ＡＳＴ）,镜下观察骨骼肌变化。结果 实验组血清中ＣＰＫ和ＡＳＴ的含量均明显低于对照组（Ｐ〈０．０５）。实验组骨骼肌线粒体空泡变     

Bradykinin Impairs and HOE 140 does not Protect Rat Hindlimb Skeletal Muscle Against Tourniquet-induced Reperfusion Injury

Background: Bradykinin (BK) is used in different tissues. Dose-dependent studies have demonstrated that low doses protect against ischemia/reperfusion (I/R) injury while higher doses lead to adverse effects. Although the beneficial effects of BK infusion were observed in myocardium, its role on the I/R impact in skeletal muscle (SM) has not been fully clarified. Objective: This study was carried out to evaluate the effects of BK, administered in the hindlimbs of rats subjected to I/R. Methods: The study design included three experimental groups: Group 1 control (saline), Group 2 (bradykinin), and Group 3 (HOE 140, a BK2 receptor blocker). In all three groups, rats were subjected to hindlimb ischemia for a total of 2 h followed by continuous 4 h of reperfusion with pharmacological interventions. The methods include analysis of enzymes (lactate dehydrogenase—LDH and creatinine phosphokinase—CPK), cell membrane marker of injury (malondialdeyde—MDA), recruitment of neutrophils (myeloperoxidase—MPO), and apoptosis index (immunohistochemistry TUNEL in situ peroxidase dead end). Results: Except for the apoptotic index, all parameters studied were shown to be elevated in the reperfusion group intervened with BK. The blocking of BK2 receptors by HOE 140 did not affect the I/R injury. Conclusion: After 2 h of total ischemia, infusion of bradykinin during 4 h of reperfusion, worsened the I/R injury in the hindlimb skeletal muscle.