A mutation influencing the transportation of manganese, L-dopa, and L-tryptophan

Transportation of manganese, L-dopa, and L-tryptophan was slower through the tissues, of intact pallid mice than through those of black C57Bl/6J mice, presumably because of the influence of the gene pallid.     

菜籽多酚级分-2的体外抗氧化作用及其机理

测定了菜籽多酚级分-2在化学模拟体系、小鼠线粒体、小鼠血清与肝匀浆中的抗氧化作用.结果表明: 在化学反应体系中, 菜籽多酚级分-2具有还原能力,能清除活性氧,抑制脂肪氧合酶的活性.在体外试验中,菜籽多酚级分-2能抑制线粒体膜的肿胀,增加小鼠血清抗活性氧能力,抑制小鼠肝线粒体与小鼠肝组织匀浆MDA(丙二醛)的生成.以上试验表明: 菜籽多酚级分-2在生物体内具有明显的抗氧化作用,高的还原能力与抑制生物体内氧化酶是菜籽多酚级分-2抗氧化的机理.     

mtDNA A3243G 点突变小鼠模型的建立及其致病机制探讨

    利用显微注射线粒体技术建立转人线粒体小鼠模型,研究外源突变mtDNA在不同组织的分布及遗传规律,探讨mtDNA A3243G点突变对线粒体功能的影响.从健康成人及2型糖尿病患者(携带mtDNA 3243A-G突变)血液标本中分离有活性的线粒体,将其显微注射至小鼠受精卵,胚胎移植,产出仔鼠后利用分子生物学方法检测人mtDNA及mtDNA A3243G点突变.获得嵌合体小鼠后,对其空腹血糖和全血乳酸进行测定,并使用荧光法和比色法分析A3243G点突变小鼠重要脏器组织细胞活性氧生成量(ROS)、线粒体复合酶Ⅰ和Ⅳ活力及线粒体ATP合成活力的变化.研究结果显示:在1只雌性(转健康人线粒体)和2只雄性小鼠(转患者线粒体)中检测到人mtDNA,其中2只雄性小鼠携带mtDNA 3243A-G突变;将嵌和体雌鼠与野生型C57BL/6J 雄鼠交配后,在1只后代仔鼠中检测到人mtDNA;人mtDNA仅在嵌合小鼠的部分组织中表达.在含有mtDNA A3243G突变的组织中发现,线粒体复合酶Ⅰ、Ⅳ活力降低,ATP合成速率下降,ROS水平升高,说明A3243G点突变能损伤线粒体正常功能从而导致疾病的发生.综上所述,本研究利用显微注射法成功建立了嵌和小鼠,引入了致病性的点突变,为线粒体疾病的研究提供了良好的思路.     

菜籽多糖的抗氧化作用与机理研究

 研究菜籽多糖粗品的抗氧化作用与机理。用K3[Fe(CN)6]与TCA体系、脂肪氧合酶评价菜籽多糖的还原能力及抑制脂肪氧合酶的能力，用丙二醛(MDA)及活性氧(ROS)试剂盒测定MDA及ROS含量，用分光光度法测定小鼠肝线粒体肿胀度。结果显示，在化学模拟体系中，菜籽多糖具有还原能力，2.00 mg·ml-1菜籽多糖的抗活性氧单位为94.03，对脂肪氧合酶的抑制率达22.8%。在体外，2.00 mg·ml-1菜籽多糖使自由基诱导的小鼠肝线粒体肿胀度低于非诱导组，对自由基诱导的小鼠肝线粒体MDA生成抑制率达30.3%，对肝组织匀浆MDA生成抑制率分别为54.7%（非诱导组）、32.0%（Fe2+诱导组）及84.5%（H2O2诱导组）。10.00 mg·ml-1菜籽多糖使小鼠血清抗活性氧单位达1 340.13。在体内，腹膜注射菜籽多糖组小鼠（400 mg·kg-1bw·d-1, 12 d）与对照组相比，肝匀浆MDA的降低达到极显著水平(P＜0.01)。以上结果表明，菜籽多糖在体内外均具有明显的抗氧化作用，菜籽多糖具有还原能力及抑制与氧化有关的酶的活性可能是其抗氧化的机理。     

Extension of murine life span by overexpression of catalase targeted to mitochondria

To determine the role of reactive oxygen species in mammalian longevity, we generated transgenic mice that overexpress human catalase localized to the peroxisome, the nucleus, or mitochondria (MCAT). Median and maximum life spans were maximally increased (averages of 5 months and 5.5 months, respectively) in MCAT animals. Cardiac pathology and cataract development were delayed, oxidative damage was reduced, H2O2 production and H2O2-induced aconitase inactivation were attenuated, and the development of mitochondrial deletions was reduced. These results support the free radical theory of aging and reinforce the importance of mitochondria as a source of these radicals.     

Respiratory control: loss in mitochondria from diseased plants

Mitochondria from healthy oat seedlings oxidized succinate with good respiratory control and high ratios of adenosine diphosphate to oxygen. After treatment with victorin, the pathotoxin responsible for symptoms of Victoria blight of oats, susceptible seedlings yielded mitochondria with little respiratory control and lower ratios of adenosine diphosphate to oxygen. No such effects were obtained with victorin-treated resistant seedlings or when victorin was added directly to mitochondria from healthy susceptible or resistant plants. These data indicate that victorin-induced disease results in a reduction in efficiency of the energy-generating system of isolated mitochondria.     

Manganese encrustation of zygospores of a chlamydomonas (chlorophyta: volvocales)

In media containing normal trace-element supplements, but not in manganese-deficient media, zygospores of a new species of Chlamydomonas (isolated from soil) become encrusted with a dark brown mineral coating. Staining with benzidine indicates that the encrustation is rich in manganese. This has been confirmed by x-ray analysis in combination with a scanning electron microscope.     

水溶性灵芝肽在动物体外的抗氧化活性

【目的】研究水溶性灵芝肽在动物体外的抗氧化活性。【方法】用丙二醛(MDA)试剂盒测定MDA含量，用分光光度法测定大鼠血清自氧化溶血及小鼠肝线粒体肿胀度。【结果】当水溶性灵芝肽的剂量为0.25 mg•ml-1时，对大鼠红细胞自氧化溶血的抑制率达62.33%，对溶血过程中MDA生成的抑制率达91.24%；在有或无自由基诱导剂（Fe2+或H2O2）时，0.35 mg•ml-1的水溶性灵芝肽均能极显著抑制小鼠肝匀浆中MDA的生成（P＜0.01），且抑制率大致相当，为60%左右；当水溶性灵芝肽剂量为1.00 mg•ml-1时，对线粒体肿胀度的抑制率为90.52%，对线粒体中MDA生成的抑制率达65.42%，且呈明显剂量-效应关系。【结论】水溶性灵芝肽在体外具有明显的抗氧化作用。     

鲈鱼和小鼠肝组织几种功能指标的比较

为探索处于不同进化地位的两种动物（鲈鱼和小鼠）肝功能指标的异同，分别采用Lowry法、CO还原差示光谱法和比色法，对鲈鱼和小鼠肝组织重要细胞器（线粒体和微粒体）蛋白、药物代谢酶（细胞色素P450）和反映肝功能的重要指标（血清中天冬氨酸转氨酶和丙氨酸氨基转移酶含量）进行了比较。结果显示，鲈鱼肝脏线粒体蛋白、细胞色素P450和丙氨酸氨基转移酶均明显低于小鼠，而微粒体蛋白和天冬氨酸氨基转移酶与小鼠差异不明显。这些结果提示，肝功能指标在不同进化地位的动物（鲈鱼和小鼠）间存在着差异，其中肝脏细胞色素P450和丙氧酸氨基转移酶的含量可能与肝功能尊异密切相关。     

鲈鱼和小鼠肝组织几种功能指标的比较

为探索处于不同进化地位的两种动物（鲈鱼和小鼠）肝功能指标的异同,分别采用Lowry法、CO还原差示光谱法和比色法,对鲈鱼和小鼠肝组织重要细胞器（线粒体和微粒体）蛋白、药物代谢酶（细胞色素P450）和反映肝功能的重要指标（血清中天冬氨酸转氨酶和丙氨酸氨基转移酶含量）进行了比较。结果显示,鲈鱼肝脏线粒体蛋白、细胞色素P450和丙氨酸氨基转移酶均明显低于小鼠,而微粒体蛋白和天冬氨酸氨基转移酶与小鼠差异不明显。这些结果提示,肝功能指标在不同进化地位的动物（鲈鱼和小鼠）间存在着差异,其中肝脏细胞色素P450和丙氧酸氨基转移酶的含量可能与肝功能尊异密切相关。     

海带岩藻黄素对小鼠脂质过氧化抑制作用的影响

用硫代巴比妥酸法测定小鼠肝组织及线粒体中丙二醛的含量,用分光光度法测定小鼠红细胞溶血和肝线粒体的肿胀程度,从而考察海带Laminaria japonica岩藻黄素对小鼠脂质体系的抗氧化能力。结果表明：岩藻黄素能在自发和诱导条件下抑制肝匀浆液及线粒体中丙二醛的产生,降低红细胞的溶血程度,并能减轻肝线粒体的肿胀程度,且其抑制作用均呈明显的剂量效应关系。这说明海带岩藻黄素具有明显的抗氧化作用。     

PLAGUE TOXIN: ITS EFFECT IN VITRO AND IN VIVO

The murine toxin of Pasteurella pestis inhibited the respiration of heart mitochondria from the rat and the mouse but had little or no effect on the respiration of mitochondria from the rabbit, chimpanzee, dog, and monkey. Alterations occurred in tile S-T segments of the electrocardiogramus recorded corded from rats injected with (1/4) to 10 LD(50) of toxin, but not in those from rats dying of hemorrhagic shock, hypoxia, intoxication with glucose, or Escherichia coli endotoxin. No abnormalities were observed in electrocardiograms from rabbits injected with large amounts of toxin.     

霍山石斛与铜皮石斛多糖体外抗氧化作用的初步研究（摘要）

[目的]初步探讨霍山石斛与铜皮石斛多糖体外抗自由基和抗脂质过氧化作用。[方法]·OH的清除作用采用Fenton反应方法测定,O2的抑制作用采用邻苯三酚自氧化体系测定,脂质过氧化产物MDA采用TBA法测定。[结果]霍山石斛、铜皮石斛多糖对·OH的半数清除浓度分别为6.79、6.75 mg/ml,对O2-的半数抑制浓度分别为3.04、3.44 mg/ml。两种石斛多糖对体外温育和Vc-Fe^2＋诱导的肝匀浆的脂质过氧化均有一定的抑制作用,并可减轻Vc-Fe~（2＋）系统诱导所致小鼠肝线粒体氧化损伤程度。[结论]霍山石斛与铜皮石斛多糖均显示了较强的体外抗氧化活性。     

桑菊饮的抗氧化及保护线粒体作用

[目的]确定桑菊饮清除超氧阴离子(O2-)、抗氧化、保护线粒体的作用,为进一步扩大桑菊饮在抗衰老方面的应用提供参考依据.[方法]以L-Cys体系体外诱导昆明小鼠脑匀浆脂质过氧化及肝、脑线粒体肿胀,以NADH-PMS-NBT系统产生O2-,然后探讨桑菊饮对脂质过氧化产物丙二醛(MDA)含量、线粒体肿胀度及O2-清除效果的影响.[结果]桑菊饮能明显抑制肝线粒体肿胀、MDA生成及清除O2-,且均呈剂量—效应关系.其中,当桑菊饮添加剂量为5.36 mg/mL时,对肝线粒体、肝匀浆、脑匀浆MDA生成的抑制率分别为50.45%、65.71%和42.3%,对NADH-PMS-NBT系统O2-的清除率为65.93%.[结论]桑菊饮具有清除O2-抗氧化及保护线粒体的功能,在抗衰老方面具有广阔的应用价值.     

枇杷叶黄酮的提取及对小鼠的抗氧化作用

旨在研究枇杷叶黄酮的体内外抗氧化作用。用微波提取方法提取黄酮,使用丙二醛(MDA)测定试剂盒测定枇杷叶黄酮对体内外MDA质量浓度影响;用分光光度法测定枇杷叶黄酮对H₂O₂诱导小鼠红细胞溶血,羟自由基测定试剂盒测定体内外血清中羟自由基,并计算DPPH自由基清除率。结果表明,枇杷叶黄酮质量浓度为0.05~4.00 g/L时具有较强的体外抗氧化能力,并能减少小鼠肝线粒体及肝匀浆MDA的生成,可抑制H₂O₂诱导的小鼠红细胞溶血;腹腔注射枇杷叶黄酮对小鼠体内肝组织MDA生成的抑制作用显著。枇杷叶黄酮具有较强的体内外抗氧化作用。     

碱提油菜子多糖的体外抗氧化活性研究

对碱提菜子多糖及其级分多糖进行了体外抗氧化活性研究.结果表明,碱提菜子粗多糖和级分多糖都能够减少小鼠肝匀浆丙二醛(MDA)的生成,抑制肝线粒体肿胀和红细胞氧化溶血.     

Reduced incidence of persistent chromosome aberrations in mice irradiated at low dose rates

A marked difference was observed between the effectiveness of high and low dose rates of ionizing radiation in producing persistent chromosome aberrations in the marrow cells of mice. Clones of cells with chromosome abnormalities were present in the marrow of all the mice previously exposed to single or fractionated doses of x-rays given at a rate of 30 rad/min. The frequency of chromosome aberrations in these mice varied from 14 to 72 percent of the cells exdmined. By contrast, none of the mice exposed to continuous gamma radiation at a low dose rate (1.45 rad/hour) showed definite clones of abnormal marrow cells, and the frequency of persistent chromosome aberrations varied from zero to 8 percent in this group.     

线粒体复合体及其对活性氧的调控研究进展

线粒体呼吸链复合体是氧化磷酸化作用的主要参与者,对生物体的生命活动具有重要意义,与活性氧的产生与调控有着密切联系。同时,对线粒体复合体的研究也是了解植物抗逆作用的一个重要途径。文中从植物线粒体呼吸链复合体的基本结构和功能、呼吸链超复合体以及呼吸链复合体在植物调控活性氧代谢的作用等几个方面进行了综述。     

Blastocladia and aqualinderella: fermentative water molds with high carbon dioxide optima

The uniflagellate aquatic phycomycete Blastocladia ramosa appears to be a facultative anaerobe. Blastocladia pringsheimii requires traces of oxygen. Growth of both species is no greater or only slightly greater at normal atmospheric oxygen pressure than under 0.2 percent oxygen pressure, but their growth is enhanced by the addition of 5 or 20 percent carbon dioxide. The cells of both species lack typical cristate mitochondria and contain only traces of cytochrome. Blastocladia resembles the biflagellate Aqualinderella fermentans in adaptation to an environment poor in oxygen and rich in carbon dioxide.     

Oxygen radicals in influenza-induced pathogenesis and treatment with pyran polymer-conjugated SOD

The pathogenicity of influenza virus infection in the mice involves, at least in part, overreaction of the immune responses of the host rather than a direct effect of virus multiplication. Xanthine oxidase, which is responsible for the generation of oxygen free radicals, was elevated in serum and lung tissue of mice infected with influenza virus. To test the theory that oxygen-free radicals are involved in pathogenesis, free radicals were removed by injecting superoxide dismutase (SOD), a specific superoxide radical scavenger, which was conjugated with a pyran copolymer. The conjugate protected mice against a potentially lethal influenza virus infection if administered 5 to 8 days after infection. These findings indicate that oxygen radicals are important in the pathogenesis of influenza virus infection, and that a polymer-conjugated SOD has therapeutic potential for this virus infection and other diseases associated with free radicals.