异丙酚对乳鼠心肌细胞缺氧/复氧损伤后凋亡的影响

目的探讨异丙酚对乳鼠心肌细胞缺氧/复氧损伤后凋亡的影响及其作用机制。方法把培养的18孔乳鼠心肌细胞随机分成3组:对照组、单纯缺氧/复氧组、异丙酚处理组。培养3 d的乳鼠心肌细胞给予1 h缺氧和3 h复氧处理（单纯缺氧/复氧组）。复氧期间给予异丙酚（25μmol/L）处理（异丙酚处理组）,复氧结束后采用DNA原位末端缺口标记技术（TUNEL）测定心肌细胞凋亡比例同时用免疫组化法测定心肌细胞内抗凋亡分子Akt、Bcl-2和促凋亡分子p38 MAPK的表达。结果与对照组相比,异丙酚显著降低了缺氧/复氧诱导的心肌凋亡（10.1%±3.2%vs25.3%±6.2%,P<0.01）,并改变了缺氧/复氧过程中凋亡介导因子的活性。免疫组化的结果显示,异丙酚增加了心肌细胞内抗凋亡蛋白pAkt和Bcl-2的形成,降低了促凋亡蛋白p38的活性。结论异丙酚对培养心肌细胞缺氧损伤后的凋亡有显著的保护作用,该作用与其对pAkt、Bcl-2和p38的影响密切相关。     

一氧化氮在乳鼠心肌细胞缺氧—复氧预处理延迟保护效应中的作用

探讨缺氧—复氧损伤对乳鼠心肌细胞一氧化氮释放和一氧化氮合酶活性的影响以及一氧化氮在心肌细胞延迟缺氧预处理中的作用。在培养乳鼠心肌细胞缺氧预处理的模型上，测定缺氧—复氧损伤对乳鼠心肌细胞一氧化氮释放和一氧化氮合酶活性，观察延迟缺氧预处理以及N-硝基-L-精氨酸、L广精氨酸、硝普钠对心肌细胞延迟缺氧预处理的影响。结果发现，缺氧—复氧后乳鼠心肌细胞一氧化氮释放增加，一氧化氮合酶活性升高。延迟缺氧预处理可以减少缺氧一复氧对心肌细胞的损伤。非选择性一氧化氮合酶抑制剂N-硝基-L-广精氨酸可以阻断延迟缺氧预处理的心肌保护作用，L广精氨酸不能模拟延迟缺氧预处理，硝普钠可以模拟延迟缺氧预处理。结果提示，一氧化氮可以诱导心肌细胞的延迟缺氧预处理。     

硫化氢对乳鼠心肌细胞缺氧-复氧损伤的保护作用

目的:研究不同浓度的硫化氢(H_2S)对缺氧不同时间的乳鼠心肌细胞损伤的直接影响及其对复氧损伤的间接影响,分析其对乳鼠心肌细胞缺氧-复氧损伤的保护作用.方法:原代培养的乳鼠心肌细胞随机分为正常对照组、缺氧硫氢化钠(NaHS)0组、缺氧硫氢化钠 100 μmol/L组、缺氧硫氢化钠 200 μmol/L组、缺氧硫氢化钠400 μmol/L组以及缺氧-复氧硫氢化钠0组、缺氧-复氧硫氢化钠100 μmol/L组、缺氧-复氧硫氢化钠 200 μmol/L组、缺氧-复氧硫氢化钠 400 μmol/L组.在缺氧24 h、48 h、72 h后及复氧2 h后均检测细胞存活数量、培养液中乳酸脱氢酶(LDH)活性.结果:缺氧硫氢化钠100 μmol/L组、缺氧硫氢化钠200 μmol/L组和缺氧硫氢化钠 400 μmol/L组缺氧培养24 h、48 h和72 h后与各自时间点缺氧硫氢化钠0组比心肌细胞存活数量升高(P<0.01)、培养液中乳酸脱氢酶活性降低(P<0.01),差异均有统计学意义;缺氧硫氢化钠 200 μmol/L组和缺氧硫氢化钠 400 μmol/L组在缺氧培养24 h后较缺氧硫氢化钠100 μmol/L组心肌细胞存活数量升高(P<0.01)、培养液中乳酸脱氢酶活性降低(P<0.05～0.01),差异均有统计学意义.缺氧-复氧硫氢化钠100 μmol/L组、缺氧-复氧硫氢化钠200 μmol/L组和缺氧缺氧-复氧硫氢化钠400 μmol/L组缺氧培养24 h、48 h、72 h并复氧2 h后较各自时间点缺氧-复氧硫氢化钠0组比心肌细胞存活数量升高(P<0.01)、复氧后心肌细胞乳酸脱氢酶漏出量降低(P<0.01),差异均有统计学意义.结论:100~400 μmol/L 硫氢化钠对缺氧-复氧心肌细胞具有保护效果.200~400 μmol/L 硫氢化钠对缺氧24 h的心肌细胞保护作用较好.     

三磷酸腺苷敏感性钾通道介导一氧化氮对缺氧/复氧鼠心肌细胞损伤的保护作用

目的　研究三磷酸腺苷敏感性钾通道 (KATP)在一氧化氮 (NO)对缺氧 /复氧心肌细胞损害中的保护作用。方法　采用细胞缺氧 /复氧损伤模型 ,培养细胞随机分为 5组 :A组 ,正常对照组(培养 3h) ;B组 ,格列本脲 (glybenclamide ,Gly ,商品名 :优降糖 )预处理组 ,加入终浓度为 10 μmol/LGly后培养 3h ;C组 ,单纯缺氧 /复氧组 (A/R缺氧 2h ,复氧 1h) ;D组 ,一氧化氮预处理组 ,加入S 亚硝基 已酰青酶胺 (S nitroso n acetyl penicillamine ,SNAP)使其终浓度为 1mmol/L ,预处理 4 0min后缺氧复氧 ;E组 ,Gly SNAP预处理组 ,加入终浓度为 10 μmol/LGly ,培育 2 0min后再加入SNAP使其终浓度为 1mmol/L ,预处理 4 0min后缺氧复氧。与复氧后测定细胞存活率 ,培养液中乳酸脱氢酶、肌酸激酶含量 ,细胞内丙二醛及游离Ca2 的变化。结果　与正常组相比 ,Gly处理组和正常组各指标无明显差别 ;与正常组相比 ,单纯缺氧 /复氧组乳酸脱氢酶、肌酸激酶、细胞内丙二醛水平显著升高 (P<0 0 1) ,与正常组相比 ,细胞存活率显著降低 (P <0 0 1)及发生明显钙超载 (P <0 0 1) ;1mmol/LSNAP预处理组明显减轻上述变化 (P <0 0 1) ;而与NO预处理组相比 ,Gly SNAP预处理组取消了NO组上述保护作用 (P <0 0 1)。结论　KATP通道参与介     

参附注射液对原代培养乳鼠心肌细胞缺氧一复氧损伤的影响

目的探讨参附注射液（SFI）对原代培养的乳鼠心肌细胞缺氧／复氧损伤的保护作用及其机制。方法建立大鼠心肌细胞原代培养缺氧／复氧损伤模型,将培养心肌细胞随机分为4组。正常对照组（C组）;缺氧／复氧组（H／R组）;低浓度SFI处理组（SFI-L组）：加入终浓度为50tlmol／mLSFI30min后再缺氧／复氧;D组：高浓度SFI处理组（SFI-H组）：加入终浓度为1（）（]umol／mI。参附注射液30rain后再缺氧／复氧。检测各组上清液中肌酸激酶同工酶（CK-MB）、心肌肌钙蛋白I（cTn-I）含量,心肌细胞内丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性以及心肌细胞凋亡指数。结果与C组比较,H,0R组心肌细胞培养液cK-MB、cTn-I含量、心肌细胞内MDA含量以及凋亡指数显著上升,SOD活性显著下降,差异有统计学意义（P〈0．01）。与H／R组比较,SFI-L组、SFI-H组中除SOD活性显著上升外,上述其他指标均显著下降,差异有统计学意义（P〈0．01）。结论SFI对缺氧／复氧损伤心肌细胞具有保护作用,其具体机制可能是与通过抑制脂质过氧化程度,减少心肌细胞凋亡有关。     

薯蓣皂苷对培养乳鼠心肌细胞缺氧／复氧损伤的保护作用

目的研究薯蓣皂苷对培养乳鼠心肌细胞缺氧／复氧损伤的保护作用并探讨其作用机制。方法采用体外培养乳鼠心肌细胞，建立缺氧／复氧损伤模型，以薯蓣皂苷进行干预。心肌细胞随机分为5组：空白对照组（C组）；缺氧／复氧组（A／R组）；薯蓣皂苷（Dioscin）低、中、高剂量干预组（Dioscin＋A／R组）。分别观察各组心肌细胞搏动频率；MTr法测细胞存活率；用Rhl23荧光探针标记线粒体，检测荧光强度以反映线粒体膜电位（△ψm）变化；Fluo-3负载心肌细胞，激光扫描共聚焦显微镜观察细胞内钙离子浓度变化。结果薯蓣皂苷干预组心肌细胞搏动频率、细胞存活率、△ψm与A／R组比较明显升高；细胞内平均钙离子荧光强度显著低于A／R组。结论从细胞水平初步证实薯蓣皂苷预处理心肌细胞对A／R损伤有一定保护作用，保护机制可能涉及对线粒体膜保护和防止细胞内钙超载等。     

西洛他唑对乳鼠心肌细胞缺氧/复氧损伤的保护作用

目的:研究西洛他唑(Cilostazol,CIL)对乳鼠心肌细胞缺氧/复氧(hypoxia/reoxygenation,H/R)损伤的影响及机制。方法:①分离培养SD乳鼠心肌细胞,建立H/R模型。心肌细胞随机分4组:对照组;H/R组,缺氧2 h,复氧4 h;H/R CIL组,缺氧前1 h予以CIL(10μmol.L-1)随即缺氧2 h,复氧4 h;H/R CIL Wort mannin(H/R CIL W)组,CIL处理前30 min予磷脂酰肌醇-3激酶(phosphatidylinositol-3 kinase PI3K)特异性抑制剂——渥曼青霉素(Wort mannin 0.1μmol.L-1);②检测各组培养液中乳酸脱氢酶、肌酸激酶同工酶含量,流式细胞术检测心肌细胞凋亡率,Western blot检测丝氨酸/苏氨酸蛋白激酶(Akt)及磷酸化丝氨酸/Akt(p-Akt)的表达。结果:CIL明显抑制H/R损伤导致的心肌细胞凋亡,并使p-Akt/Akt比值明显增加;Wort mannin可使p-Akt/Akt比值明显减少,抑制CIL的抗凋亡作用。结论:H/R损伤可导致心肌细胞凋亡,CIL可能通过PI3K-Akt途径发挥抗凋亡作用。     

当归、红芪超滤膜提取物对培养乳鼠心肌细胞缺氧-复氧损伤的影响

目的 探讨当归、红芪超滤膜提取物对心肌细胞缺氧/复氧损伤的影响.方法 通过给原代培养乳鼠心室肌细胞进行缺氧1 h/复氧1 h,建立缺氧/复氧(A/R)心肌细胞损伤模型.于复氧期开始随机将心肌细胞分为正常对照组(C)、缺氧/ 复氧组(A/R组)、药物低剂量组(LD)、药物高剂量组(HD),于药物作用24 h后测定各组缺氧/复氧后细胞损伤指标肌酸激酶(CK)、丙二醛(MDA)、超氧化物歧化酶(SOD)、髓过氧化物酶(MPO).结果 LD、HD组MDA、MPO、肌酸激酶(CK)明显较A/R组降低(P<0.01),SOD明显增高(P<0.01).结论 当归、红芪超滤膜提取物(10万分子量)可减轻心肌细胞缺氧/复氧损伤.     

生脉注射液对乳鼠心肌细胞缺氧复氧损伤的保护作用

目的探讨生脉注射液对纯化培养的乳鼠心肌细胞缺血再灌注损伤的保护作用。方法采用纯化培养的乳鼠心肌细胞建立缺氧复氧损伤模型,随机分为正常对照组、缺氧复氧损伤组、缺氧复氧损伤＋维拉帕米组、缺氧复氧损伤＋生脉注射液组,分别测定其乳酸脱氢酶（LDH）活性、超氧化物歧化酶（SOD）活性、丙二醛（MDA）及ATP水平。结果生脉注射液可明显提高LDH、SOD活性,降低MDA、提高ATP水平。结论生脉注射液具有明显的抗缺氧复氧损伤、保护心肌的作用。     

缺氧预处理对乳兔心肌细胞缺氧复氧损伤的保护研究

目的：观察预处理（ＰＣ）对乳兔心肌细胞缺氧复氧（Ａ－Ｒ）损伤的影响。方法：采用心肌细胞Ａ－Ｒ模型，用短暂缺氧进行预处理。结果：缺氧预处理能提高Ａ－Ｒ后心肌细胞存活率（７７．２１±３．１０ＶＳＡ－Ｒ组５９．８３±２．１０．Ｐ＜０．０１）．减少ＭＤＡ产生（０．７５±０．０２ＶＳＡ－Ｒ组１．６１±０．０８ｎｍｏｌ／ｍｇｐｒ，Ｐ＜０．０１）及乳酸脱氢酶的漏出（Ｐ＜０．０１）。结论：离体乳兔心肌细胞存在ＰＣ保护现象。     

比索洛尔对缺氧/复氧内皮细胞一氧化氮生成的影响

目的 :观察比索洛尔对培养的人脐静脉内皮细胞 （HU VECs）在缺氧 /复氧 （A/ R）过程中一氧化氮 （NO）生成的影响。方法 :将 HUVECs暴露于缺氧环境中 30 m in后复氧 ,并加入比索洛尔 （1,5 0和 5 0 0 μmol/ L）或空白对照 ,测量复氧前、复氧后 1和 4h培养液上清 NO含量。结果 :对照组 NO产量在复氧后 1h,4h与复氧前相比有显著下降 （均 P<0 .0 1）。比索洛尔 5 0 μm ol/ L 组和 5 0 0 μmol/ L 组 NO产量在复氧后 1h,4h与复氧前相比无显著差异 （均P>0 .0 5 ） ,而与对照组和 1μmol/ L 组同一时间相比均有显著增加 （均 P<0 .0 1）。结论 :比索洛尔可以阻止 A/ R期间内皮细胞 NO产量的下降 ,因此 NO可能参与了 β阻滞剂减少缺血再灌注损伤的过程。     

Biglycan protects cardiomyocytes against hypoxia/reoxygenation injury: Role of nitric oxide

Biglycan, a proteoglycan component of extracellular matrix, has been suspected to contribute to the development of atherosclerosis, but overexpression of biglycan in transgenic mice has been shown to induce cardioprotective genes including nitric oxide (NO) synthases in the heart. Therefore, here we hypothesized if exogenous administration of biglycan exerts cytoprotection. Primary cardiomyocytes from neonatal rats were subjected to 150 min hypoxia and 2 h reoxygenation. Mortality of cardiomyocytes was dose-dependently attenuated by pretreatment with 1-100 nM biglycan. Biglycan enhanced eNOS mRNA and protein, and significantly increased NO content of cardiomyocytes. The NO synthase inhibitor l-nitro-arginine-methyl-ester significantly attenuated the cytoprotective effect of biglycan. This is the first demonstration that biglycan leads to cytoprotection against hypoxia/reoxygenation injury, and that this phenomenon is partially mediated by an NO-dependent mechanism.     

一氧化氮对缺氧复氧处理的新生大鼠心肌细胞蛋白质酪氨酸磷酸酶-1B活性和表达的影响

目的 验证缺氧复氧诱发的新生大鼠心肌细胞蛋白质酪氨酸磷酸酶-1B(PTP-1B)的表达和活性的增加是否由一氧化氮(NO)介导.方法 分离的新生大鼠心肌细胞,随机分为正常组、缺氧复氧组、非特异性一氧化氮合成酶抑制剂L-NAME组(L-NAME组)、缺氧复氧和L-NAME组(L-NA+H/R组).心肌细胞中PTP-1B的活性和表达分别由405 nm的光谱测量仪和Western blot法检测.同时分析心肌细胞培养基中的NO的浓度和乳酸脱氢酶活性.结果 与正常组比较,缺氧复氧组中心肌细胞PTP-1B的活性和表达较高,(L-NA+H/R)组PTP-1B的活性和表达不高.与缺氧复氧组比较,(L-NA+H/R)组NO和乳酸脱氢酶浓度显著低.缺氧复氧组和L-NA+H/R组中的NO含量分别是正常组(100%)的(368±13)%和(61±7)%(P<0.005);缺氧复氧组、L-NAME+H/R组中的乳酸脱氢酶的活性值分别为41.2±6.7和23.6±4.8(P<0.05).结论 L-NAME预处理阻止了缺氧复氧诱发的大鼠心肌细胞中PTP-1B活性和表达的增加,提示缺氧复氧期间PTP-1B的变化是由NO介导的.     

Beneficial effects of low doses of ethanol on reoxygenation injury following anoxia in rat hearts

Summary We investigated the effect of ethanol on adverse effects of anoxia and reoxygenation in isolated rat hearts. Perfusion of the anoxic Krebs-Henseleit medium for 40 min followed by 30 min of perfusion with aerobic medium produced considerable myocardial cell injury. Incorporation of ethanol (21.7 mM), in both anoxic and aerobic perfusion media resulted in a significant reduction of cell injury and inhibition of creatine phosphokinase release. The contraction bands were reduced to 0.24 as compared to 1.14 per field in the non-treated hearts. The tissue CA⁺⁺ was decreased to 8.72 μmol/gm/dry wt as compared to 20.17 μmol/gm/dry weight in the non-treated hearts and tissue ATP was increased by 50 % in the treated tissue (8.14 μmol/gm/dry wt), as compared to the nontreated anoxic tissue (4.41 μmol/gm/dry wt). However, the inclusion of only ethanol in the anoxic medium did not decrease the damage, suggesting that maximal injury occurred during reoxygenation. Ethanol appears to inhibit myofibril contractures and preserve the structural integrity of plasma membrane during anoxia and reoxygenation. This study suggests a beneficial effect of ethanol in low doses on the post anoxic reperfusion injury in the myocardium.     

The nitric oxide system response to hypoxia/reoxygenation in the aged cerebral cortex

Aged individuals are more susceptible to hypoxic insults, but little is known about the response of the nitric oxide (NO) system to hypoxia in the senescent brain. We have analysed the effect of aging on the hypobaric hypoxia/reoxygenation NO synthase (NOS) expression and activity in the cerebral cortex. In aged animals, the absence of significant changes in NOx and activity indicates a weaker response of the systems involving NO production in this pathological situation. The nNOS protein levels remained invariable and similar in both age groups after hypoxia, although in aged animals the mRNA did not change and was consistently lower than in adults. Both eNOS mRNA and protein increased shortly after hypoxia. However, although eNOS protein levels were quite similar in both age groups, the increase appeared later and was less persistent in aged animals. Real-time RT-PCR revealed a similar basal inducible NOS (iNOS) mRNA expression that responded late in reoxygenation, mainly in aged rats. However, neither iNOS protein nor activity was detected in any age group. Altogether our results indicate that aging attenuates the response of the NO system to a hypoxic injury, particularly at eNOS level, the activity of which is crucial for maintaining vascular homeostasis.     

SIRT6-shRNA预处理对缺氧/复氧诱导的H9C2心肌细胞损伤的影响及其机制

目的 探讨通过RNA干扰技术抑制H9C2心肌细胞内的SIRT6基因表达对缺氧/复氧(A/R)诱导的细胞损伤的影响和机制。方法 将H9C2心肌细胞随机分为正常对照组(Con组)、A/R组、阴性对照SIRT6-shRNA质粒处理组(NC组)和SIRT6-shRNA质粒处理组(shRNA组)。检测4组H9C2心肌细胞的存活率、凋亡率、Caspase-3活性及SIRT6、核因子(NF)-κBp65、I-κBα表达水平及细胞培养液中白细胞介素(IL)-6和肿瘤坏死因子(TNF)-α水平并进行比较。结果 与Con组相比,A/R组H9C2心肌细胞存活率和细胞浆中I-κBα蛋白表达水平明显降低,凋亡率、细胞SIRT6-mRNA和蛋白、细胞核中NF-κBp65蛋白表达水平、细胞培养液中IL-6和TNF-α水平及Caspase-3活性明显升高（P<0.05）。与A/R组比较,shRNA组H9C2心肌细胞存活率、细胞SIRT6-mRNA和蛋白及细胞浆中I-κBα蛋白表达水平明显降低,细胞凋亡率、细胞核中NF-κBp65蛋白、细胞培养液中IL-6和TNF-α水平及Caspase-3活性明显升高(P<0.05)。结论 抑制H9C2心肌细胞内SIRT6基因表达能促进炎症因子的分泌,激活NF-κB信号通路,诱导细胞凋亡,加重A/R诱导的心肌细胞损伤。     

The PPAR-γ agonist rosiglitazone facilitates Akt rephosphorylation and inhibits apoptosis in cardiomyocytes during hypoxia/reoxygenation

Background and Aim: Results on the cardiovascular effects of PPAR‐γ agonists are conflicting. On one hand, it was suggested that the PPAR‐γ agonist rosiglitazone may increase the risk of cardiovascular events. On the other hand, PPAR‐γ agonists reduce myocardial infarct size and improve myocardial function during ischemia/reperfusion in animal studies in vivo. However, the mechanism of this effect is unclear, and it is open if PPAR‐γ agonists have a direct effect on cardiac myocyte survival in ischemia/reperfusion. The aim of this study was to determine the effect of the PPAR‐γ agonist rosiglitazone on hypoxia/reoxygenation‐induced apoptosis of isolated cardiomyocytes. Methods: Isolated rat cardiac myocytes were pretreated with rosiglitazone or vehicle for 30 min before they were subjected to hypoxia for 4 h followed by different times of reoxygenation (5 min to 12 h). Apoptosis was determined by in situ hybridization for DNA fragmentation (TUNEL) as well as detection of cytoplasmic accumulation of histone‐associated DNA fragments by enzyme‐linked immunosorbent assay (ELISA). Activation of apoptosis regulating intracellular signalling pathways was studied by immunoblotting using phosphospecific antibodies. Results: Rosiglitazone significantly reduced apoptosis of isolated cardiomyocytes subjected to hypoxia/reoxygenation, independently determined with two methods. After 4 h of hypoxia and 12 h of reoxygenation, 34 ± 3.6% of the vehicle treated cardiac myocytes stained positive for DNA fragmentation in the TUNEL staining. Rosiglitazone treatment reduced this effect by 23% (p < 0.01). Even more pronounced, cytoplasmic accumulation of histone‐associated DNA fragments detected by ELISA was reduced by 35% (p < 0.05) in the presence of rosiglitazone. This inhibition of hypoxia/reoxygenation‐induced apoptosis was associated with an increased reoxygenation‐induced rephosphorylation of the protein kinase Akt, a crucial mediator of cardiomyocyte survival in ischemia/reperfusion of the heart. This effect was reversed by GW‐9662, an irreversible PPAR‐γ antagonist. However, rosiglitazone did not alter phosphorylation of the MAP kinases ERK1/2 and c‐Jun N‐terminal kinase (JNK). Conclusion: It can be concluded that cardiac myocytes are direct targets of PPAR‐γ agonists promoting its survival in ischemia/reperfusion, at least in part by facilitating Akt rephosphorylation. This effect may be of clinical relevance inhibiting the reperfusion‐induced injury in patients suffering from myocardial infarction or undergoing cardiac surgery.     

银杏内酯B减轻血管内皮细胞缺氧/复氧损伤的作用

目的:探讨银杏内酯B(GB)减轻缺氧/复氧(H/R)所致血管内皮细胞损伤的作用和机制。方法: 将体外培养的人脐静脉内皮细胞分为5个组,即空白对照组（不加任何处理）、GB组（100 μmol/L）、H/R组（缺氧2 h/复氧24 h）、GB+H/R组及GB+H/R+ N-硝基-L-精氨酸甲酯（L-NAME,NOS抑制剂）组。用3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐（MTT）比色法测定内皮细胞的存活率(%)。用乳酸脱氢酶（LDH）测试盒和一氧化氮（NO）测试盒分别检测细胞培养上清液中LDH和NO的含量。用Western blot法检测培养的人脐静脉内皮细胞中内皮型一氧化氮合成酶（eNOS）表达的水平。结果: MTT比色法的结果显示,H/R可显著降低内皮细胞的存活率(%),增加LDH的含量,降低NO的生成量（与空白对照组比较,P<0.01）;而GB则可逆转上述效应,但GB的作用又可被L-NAME所抑制（与GB+H/R组比较,P<0.01）。GB可以显著提高H/R作用后血管内皮细胞中eNOS表达的水平（与H/R组比较,P<0.01）,但是该效应不被L-NAME阻断。结论: GB可显著减轻H/R对内皮细胞的损伤,其作用是通过eNOS-NO途径实现的。