共查询到19条相似文献,搜索用时 171 毫秒
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背景:小鼠间充质细胞在体外培养扩增困难,细胞凋亡是否是其原因之一,目前未知.目的:观察常氧和低氧条件下,小鼠肺间充质细胞的凋亡率是否有差别.方法:用组织块培养法获得 C57BL/6J 雄性小鼠肺间充质细胞,分别在常氧(体积分数 20%氧)和低氧(体积分数 5%的氧)条件下培养,观察细胞内活性氧水平、凋亡率和超微结构的变化.结果与结论:体积分数为 5%和 20%氧气培养的细胞随代数的增加造血细胞均逐渐减少.体积分数20%氧气培养的小鼠肺间充质细胞内的活性氧水平明显高于体积分数 5%氧气培养的细胞.体积分数 20%氧气培养的肺间充质细胞的凋亡现象较常见,体积分数 5%氧气培养的细胞凋亡现象较少见.提示常氧培养条件下,细胞的凋亡率增加,降低氧浓度可减少细胞的凋亡率. 相似文献
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目的:自行设计细胞模型并观察缺氧条件下维生素E对培养视网膜色素上皮细胞生长的影响。方法:实验于2006-10/2007-03在南京医科大学生理实验室完成。①实验操作:取对数生长期的细胞,以正常条件为对照(常规培养和体积分数为0.95的空气,体积分数为0.05的CO2),建立人视网膜色素上皮细胞的缺氧模型(缺氧培养,体积分数为0.95的N2和体积分数为0.05的CO2混合气体,测氧仪测氧浓度<1%,24h),作用于细胞的维生素E浓度分别为0.1,0.2,0.3mol/L。②实验评估:四甲基偶氮唑盐法检测24h细胞活力(以吸光度A值表示);激光共聚焦显微镜检测细胞内活性氧水平;黄嘌呤氧化酶法测定细胞内超氧化物歧化酶活性。结果:①四甲基偶氮唑盐检测细胞生长活力:缺氧组细胞活力低于对照组(P<0.01),缺氧 维生素E组细胞活力有所提高,与缺氧组相比,差异显著(P<0.05)。随着维生素E浓度的提高,活力逐渐升高。②细胞内活性氧水平:与对照组比较,缺氧组细胞内活性氧的产生明显增多;与缺氧组比较,缺氧 维生素E组抑制视网膜色素上皮细胞内活性氧的产生。③超氧化物歧化酶活力检测:与对照组比较,缺氧组超氧化物歧化酶的活力降低;与缺氧组比较,缺氧 维生素E组超氧化物歧化酶活力升高,差异均具有显著性意义(P<0.05)。结论:缺氧引起视网膜色素上皮细胞氧化应激损伤,维生素E抑制了缺氧情况下视网膜色素上皮细胞的损伤作用,维生素E主要通过提高超氧化物歧化酶活性来发挥抗氧化损伤作用,其抗氧化损伤作用有剂量依赖性。 相似文献
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目的探讨银杏内酯K对心肌缺血的保护作用及其作用机制。方法将H9C2心肌细胞暴露于氧糖剥夺(OGD)条件下,体外模拟缺血缺氧模型。暴露于OGD 4 h后,给予不同浓度(12. 5μg/ml、25μg/ml、50μg/ml)的银杏内酯K孵育H9C2细胞1 h。对照组细胞仅在OGD实验时换为高糖DMEM,不做其他处理。培养结束后检测H9C2细胞的细胞活力、活性氧(ROS)含量;流式细胞术检测细胞凋亡;荧光实时定量PCR检测H9C2细胞内p38 MAPK和JNK的表达水平。结果与对照组相比,银杏内酯K能显著提高细胞活力,且呈剂量依赖性。与对照组相比,OGD组ROS含量显著增加(P 0. 05),不同浓度12. 5μg/ml、25μg/ml、50μg/ml的银杏内酯K处理H9C2细胞1 h,可显著减少各组细胞内ROS含量,抑制各组细胞凋亡,显著降低H9C2细胞内p38 MAPK和JNK的mRNA表达水平(P 0. 05),且呈剂量依赖性。结论银杏内酯K对体外模拟的心肌缺血具有保护作用,其作用机制与通过抑制ROS诱发的p38和JNK激活所致凋亡通路有关。 相似文献
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目的:探讨右旋美托咪啶(DEX)在大鼠海马神经元细胞中对缺氧缺糖(OGD)损伤导致的细胞凋亡的影响。方法:取培养8 d的原代新生大鼠海马神经元细胞随机分为4组:正常对照组、OGD模型组、DEX对照组和DEX处理组。建立大鼠原代海马神经元缺氧缺糖/复氧复糖损伤模型,JC-1荧光探针检测细胞线粒体膜电位(MMP)变化,DCFH-DA染色检测细胞内活性氧(ROS)水平变化。结果:与对照组相比,OGD损伤可明显降低细胞内MMP水平,而右旋美托咪啶预处理可抑制MMP的降低,并可抑制OGD介导的ROS生成。结论:右美托咪啶对大鼠海马神经元OGD损伤具有保护作用,其机制与抑制ROS生成和抑制MMP下降相关。 相似文献
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Intermittent hypoxic training: implications for lipid peroxidation induced by acute normoxic exercise in active men. 总被引:7,自引:0,他引:7
Oxidant generation during regular physical exercise training may influence the adaptive responses that have been shown to confer protection against oxidative stress induced by subsequent acute exercise. To examine this, we randomly assigned 32 males to either a normoxic (n=14) or a hypoxic (n=18) group. During the acute phase, subjects in the hypoxic group performed two maximal cycling tests in a randomized double-blind fashion: one under conditions of normoxia and the other under hypoxic conditions (inspired fraction of O(2)=0.21 and 0.16 respectively). During the intermittent phase, the normoxic and hypoxic groups each trained for 4 weeks at the same relative exercise intensity, under conditions of normoxia and hypoxia respectively. During acute exercise under hypoxic conditions, the venous concentrations of lipid hydroperoxides and malondialdehyde were increased, despite a comparatively lower maximal oxygen uptake (VO(2max)) (P<0.05 compared with normoxia). The increases in lipid hydroperoxides and malondialdehyde were correlated with the exercise-induced decrease in arterial haemoglobin oxygen saturation (r=-0.61 and r=-0.50 respectively; P<0.05), but not with VO(2max). Intermittent hypoxic training attenuated the increases in lipid hydroperoxides and malondialdehyde induced by acute normoxic exercise more effectively than did normoxic training, due to a selective mobilization of alpha-tocopherol (P<0.05). The latter was related to enhanced exercise-induced mobilization/oxidation of blood lipids due to a selective increase in VO(2max) (P<0.05 compared with normoxic group). We conclude that lipid peroxidation induced by acute exercise (1) increases during hypoxia; (2) is not regulated exclusively by a mass action effect of VO(2); and (3) is selectively attenuated by regular hypoxic training. Oxidative stress may thus be considered as a biological prerequisite for adaptation to physical stress in humans. 相似文献
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Despite intensive treatment, the outcome of high-risk neuroblastoma patients is poor with acquired multidrug resistance as an important cause. Previously, our group has shown that arsenic trioxide (As(2)O(3)) kills multidrug-resistant neuroblastoma cells in vitro and in vivo at clinically tolerable doses. Regions of tissue hypoxia often arise in aggressive solid tumors, and hypoxic tumors exhibit augmented invasiveness and metastatic ability in several malignancies. Furthermore, hypoxia may impair the treatment efficiency; therefore, we have studied the cytotoxic effect of As(2)O(3) on neuroblastoma cells grown under normoxic as well as hypoxic (1% oxygen) conditions. At both normoxia and hypoxia, 2 and 4 mumol/L As(2)O(3) induced evident cell death in the drug-sensitive SH-SY5Y and IMR-32 cells as well as in the multidrug-resistant SK-N-BE(2)c (with a mutated p53) and SK-N-FI cells after 72 hours of exposure. In contrast, the conventional chemotherapeutic drug etoposide showed lowered efficiency in hypoxic IMR-32 cells. In accordance with our previously published results, although not to the same extent as in their normoxic counterparts, Bax is proteolytically cleaved also in neuroblastoma cells exposed to As(2)O(3) at hypoxia. This suggests that similar molecular mechanisms are involved in As(2)O(3)-induced neuroblastoma cell death during hypoxia compared with normoxia. Together, our results support As(2)O(3) as a potential candidate drug as a complement to conventional treatments for high-risk neuroblastoma patients and perhaps also for patients with other multidrug-resistant solid tumors. 相似文献
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目的 探究缺氧环境下子宫内膜腺上皮细胞(endometrial glandular epithelial cell, EEC)中微RNA(micro-RNA,miRNA)表达谱变化及其对凋亡的影响。方法 取对数生长期EEC,接种至六孔板(1×105个细胞/孔)并随机分为缺氧组和对照组。缺氧组、对照组分别置于缺氧环境(O2∶N2∶CO2体积比为1∶94∶5)和正常氧环境(O2∶CO2体积比为95∶5)中培养。培养4 h后收集细胞,加入Trizol并提取总RNA。采用高通量测序法测定两组EEC中miRNA表达谱变化,采用实时荧光定量PCR(realtime fluorescence quantitative polymerase chain reaction, RT-PCR)法检测miR-7704、miR-7974基因表达水平,采用流式细胞术检测EEC凋亡情况,采用蛋白印迹法(Western blot)检测p53和凋亡相关蛋白表达变化。结果 高通量测序对21种... 相似文献
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Regulation of glycolytic enzyme activity during chronic hypoxia by changes in rate-limiting enzyme content. Use of monoclonal antibodies to quantitate changes in pyruvate kinase content. 总被引:1,自引:1,他引:1 下载免费PDF全文
A J Hance E D Robin L M Simon S Alexander L A Herzenberg J Theodore 《The Journal of clinical investigation》1980,66(6):1258-1264
Monoclonal antibodies were prepared against pyruvate kinase (PyKi; ATP: pyruvate phosphotransferase, EC 2.7.1.40) and used to quantitate PyKi content in L2 lung cells and WI-38 fibroblasts cultivated under hypoxic and normoxic conditions. After 96 h of hypoxic cultivation, PyKi activity was significantly increased in both cell types (L2: normoxia [Po2 = 142 torr], 0.11 +/- 0.01 [SD]; hypoxia [Po2 = 14 torr], 0.25 +/- 0.04 U/microgram DNA, P < 0.01). PyKi content increased proportionately in both cell lines (L2: normoxia, 0.44 +/- 0.13; hypoxia, 0.94 +/- 0.13 microgram enzyme protein/microgram DNA). Specific activity was not significantly different after 96 h (L2: normoxia, 261 +/- 11; hypoxia, 261 +/- 14 U/mg enzyme protein). These results indicate that regulation of glycolysis during chronic hypoxia occurs at the level of enzyme content. Chronic O2 depletion leads to either an increased rate of biosynthesis or a decreased rate of biodegradation of PyKi, causing augmented glycolytic capacity. Monoclonal antibodies provide a highly specific, convenient approach to charcterizing enzymes, as well as quantitating cellular enzyme content. 相似文献
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目的:观察单纯低氧及低氧复合运动对大鼠骨骼肌线粒体解偶联蛋白3(UCP3)表达的影响,并探讨其对线粒体能量转换和活性氧(ROS)生成的影响。方法:30只健康雄性SD大鼠随机分为:常氧对照组(NC,n=10)、单纯低氧组(HC,n=10)和低氧复合运动训练组(HT,n=10)。低氧干预为常压低氧帐篷,模拟11.3%的氧浓度,运动干预为低氧帐篷内53%VO2max强度的跑台训练,1h/d。4周后测定线粒体呼吸功能、ATP合成酶活力、ROS生成速率、UCP3mRNA和UCP3蛋白表达。结果:HC与NC组比较,态3呼吸速率(ST3)、呼吸控制比(RCR)、磷氧比(ADP/O)、ATP合成酶活力、UCP3mRNA和蛋白表达均显著降低(P<0.05—0.01),ROS生成速率升高(P<0.05)。HT与HC组比较,ST3、RCR、ADP/O、ATP合成酶活力、UCP3mRNA和蛋白表达均显著升高(P<0.05—0.01),ROS生成速率降低(P<0.05)。结论:低氧复合运动可上调骨骼肌线粒体UCP3表达,抑制ROS过度生成,并通过上调ATP合成酶活力,保持线粒体能量转换效率。 相似文献
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背景:低氧可通过多种途径作用于成骨细胞影响骨代谢,对骨生成、骨愈合等产生负面影响。目的:观察低氧对体外培养大鼠成骨细胞增殖、分化的影响,并探讨其分子机制。方法:分离培养新生Wistar大鼠颅盖骨成骨细胞,取第2代细胞分别在常氧(体积分数20%O2)与低氧(体积分数3%O2)条件下培养。结果与结论:低氧组成骨细胞增殖、碱性磷酸酶活性、骨钙素水平及茜素红结节形成数量均明显低于常氧组(P〈0.05或P〈0.01),说明缺氧条件对成骨细胞的增殖、分化及功能有抑制作用;低氧组骨形成发生蛋白2及Runx2表达低于常氧组(P〈0.05或P〈0.01),说明低氧条件下大鼠成骨细胞Runx2、骨形成发生蛋白2的表达受抑制。结果表明低氧可通过抑制大鼠成骨细胞的Runx2、骨形成发生蛋白2的表达进一步抑制成骨细胞的增殖与分化。 相似文献