Journal of free radicals in biology & medicine最新文献

Intracellular damages induced by singlet oxygen are signals for HIV-1 Reactivation 单线态氧诱导的细胞内损伤是HIV-1再激活的信号

Journal of free radicals in biology & medicine Pub Date : 1994-01-01 DOI: 10.1007/978-3-0348-7424-3_23

S. Legrand-Poels, J. Piette

引用次数: 0

A demonstration that o2− is a crucial intermediate in the high quantum yield luminescence of luminol 证明氧−是鲁米诺高量子产率发光的关键中间体

Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80058-7

E.Ka. Miller, I. Fridovich

引用次数: 21

Changes in synaptic transmission produced by hydrogen peroxide 过氧化氢引起的突触传递的变化

Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80063-0

Carol A. Colton , Joel S. Colton , Daniel L. Gilbert

{"title":"Changes in synaptic transmission produced by hydrogen peroxide","authors":"Carol A. Colton , Joel S. Colton , Daniel L. Gilbert","doi":"10.1016/S0748-5514(86)80063-0","DOIUrl":"10.1016/S0748-5514(86)80063-0","url":null,"abstract":"<div>The effect of hydrogen peroxide (H2O2) on excitatory and inhibitory synaptic transmission was studied at the lobster neuromuscular junction. H2O2 produced a dose dependent decrease in the amplitude of the junction potential (Vejp). This decrease was due to changes in both presynaptic transmitter release and the postsynaptic response to the neurotransmitter. Observed presynaptic changes due to exposure to H2O2 were a decrease in the amount of transmitter released, that is, quantal content, as well as a decrease in the fast facilitation, that is, the amplitude increase of successive excitatory junction potentials at a rate of 3 Hz. To discern postsynaptic changes, glutamate, the putative excitatory neurotransmitter for this preparation was applied directly to the bathing medium in order to bypass the presynaptic release process. H2O2 produced a decreased response of the glutamate receptor/ ionophore. The action of H2O2 was not selective to excitatory (glutamate-mediated) transmission because inhibitory (GABA-mediated) transmission was also depressed by H2O2. This effect was primarily presynaptic since H2O2 produced no change in the postsynaptic response to applied GABA.</div>","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 2","pages":"Pages 141-148"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0748-5514(86)80063-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14161705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 35

Prooxidant action of desferrioxamine: Fenton-like production of hydroxyl radicals by reduced ferrioxamine 去铁胺的促氧化作用:通过还原的铁胺产生fenton样羟基自由基

Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80004-6

Donald C. Borg, Karen M. Schaich

{"title":"Prooxidant action of desferrioxamine: Fenton-like production of hydroxyl radicals by reduced ferrioxamine","authors":"Donald C. Borg, Karen M. Schaich","doi":"10.1016/S0748-5514(86)80004-6","DOIUrl":"10.1016/S0748-5514(86)80004-6","url":null,"abstract":"<div>It is common practice in biochemical research to assume that iron bound to desferrioxamine (DFO) to form ferrioxamine (FOA) has been rendered inactive to subsequent redox chemistry within the range of physiological redox potentials, both in vitro and in vivo. However, plants and microorganisms can make iron metabolically available from ferrioxamine and closely related trihydroxamate siderophores, and at neutral pH, cyclic voltammetry of FOA demonstrates a reversible one-electron reduction at about −0.42 to −0.45 V (vs. normal hydrogen electrode), which is within the range of a number of reducing enzymes. We present evidence for the Fenton-like ability of FOA reduced by paraquat cation radicals to consume H2O2 and produce hydroxyl radicals (OH·) in the process. Similar reactions may explain previously reported potentiation of the oxidizing toxicity of paraquat in rats by high doses of DFO, as well as several other examples of prooxidant actions of DFO in vivo. We present the hypothesis that biphasic antioxidant/prooxidant behavior of DFO as a function of dose may be common with iron-catalyzed oxidizing reactions when mobile strong reducing agents are present. Hence, the real possibility of amplifying oxidizing damage must be considered when planning treatment with DFO, and failure of DFO to inhibit a particular response to oxidizing stress or its enhancement by DFO cannot, by itself, be considered sufficient evidence to rule out an iron-dependent process.</div>","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 4","pages":"Pages 237-243"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0748-5514(86)80004-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14167877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 70

Oxidant-mediated lung disease in newborn infants 新生儿氧化介导的肺部疾病

Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80038-1

H.E. Evans , W. Rosenfeld , R. Jhaveri , L. concepcion , I. Zabaleta

{"title":"Oxidant-mediated lung disease in newborn infants","authors":"H.E. Evans , W. Rosenfeld , R. Jhaveri , L. concepcion , I. Zabaleta","doi":"10.1016/S0748-5514(86)80038-1","DOIUrl":"10.1016/S0748-5514(86)80038-1","url":null,"abstract":"<div>High concentrations of oxygen are administered with increased airway pressure to most preterm neonates with respiratory distress syndrome (RDS). Among 20% to 30% of survivors a form of chronic lung disease, bronchopulmonary dysplasia (BPD), develops. Its pathogenesis may include tissue damage caused by the superoxide anion (O2−) and other free oxygen radicals. Animal experiments and other data suggested a rationale for superoxide dismutase (SOD) administration in an effort to prevent or ameliorate BPD. Our preliminary studies in 19 prematures with RDS demonstrated its safety in human newborns and permitted measurement of its plasma levels. No adverse clinical findings occurred, and laboratory parameters were unchanged. Subcutaneous administration (0.25 mg/kg) of bovine SOD led to detectable levels at 1 1/2 h (mean 0.22 μg/ml), with a slight rise to a higher peak at 2 1/2–4 h and a plateau over the remainder of the 12-h interval. Following doses 2-5, peak levels of 0.64 μg/ml occurred at 4–8 h. With this background, a prospective double-blind controlled study of 45 neonates (mean gestational age, 29 weeks; birth weight, 1,100 g) showed a statistically significant reduction in prevalence of clinical and X-ray signs of BPD with fewer days of continuous positive airway pressure required. The safety and pharmacokinetics of bovine SOD were confirmed.</div>","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 5","pages":"Pages 369-372"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0748-5514(86)80038-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14426780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 16

Intracellular proteolytic systems may function as secondary antioxidant defenses: An hypothesis 细胞内蛋白水解系统可能作为次级抗氧化防御:一种假设

Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80066-6

Kelvin J.A. Davies

{"title":"Intracellular proteolytic systems may function as secondary antioxidant defenses: An hypothesis","authors":"Kelvin J.A. Davies","doi":"10.1016/S0748-5514(86)80066-6","DOIUrl":"10.1016/S0748-5514(86)80066-6","url":null,"abstract":"<div>In recent years it has become clear that various free radicals and related oxidants can cause serious damage to intracellular enzymes and other proteins. Several investigators have shown that in extreme cases this can result in an accumulation of oxidatively damaged proteins as useless cellular debris. In other instances, proteins may undergo scission reactions with certain radicals/oxidants, resulting in the direct formation of potentially toxic peptide fragments. Data has also been gathered (recently) demonstrating that various intracellular proteolytic enzymes or systems can recognize, and preferentially degrade, oxidatively damaged proteins (to amino acids). In this hypothesis paper I present evidence to suggest that proteolytic systems (of proteinases, proteases, and peptidases) may function to prevent the formation or accumulation of oxidatively damaged protein aggregates. Proteolytic systems can also preferentially degrade peptide fragments and may thus prevent a wide variety of potentially toxic consequences. I propose that many proteolytic enzymes may be important components of overall antioxidant defenses because they can act to ameliorate the consequences of oxidative damage. A modified terminology is suggested in which the primary antioxidants are such agents as vitamin E, β-carotene, and uric acid and such enzymes as Superoxide dismutase, glutathione peroxidase, and DT-diaphorase. In this classification scheme, proteolytic systems, DNA repair systems, and certain lipolytic enzymes would be considered as secondary antioxidant defenses. As secondary antioxidant defenses, proteolytic systems may be particularly important in times of high oxidative stress, during periods of (primary) antioxidant insufficiency, or with advancing age.</div>","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 3","pages":"Pages 155-173"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0748-5514(86)80066-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14675881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 267

Augmentation of antioxidant enzymes in vascular endothelium 血管内皮中抗氧化酶的增加

Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80036-8

Joseph S. Beckman, Robert L. Minor Jr., Bruce A. Freeman

{"title":"Augmentation of antioxidant enzymes in vascular endothelium","authors":"Joseph S. Beckman, Robert L. Minor Jr., Bruce A. Freeman","doi":"10.1016/S0748-5514(86)80036-8","DOIUrl":"10.1016/S0748-5514(86)80036-8","url":null,"abstract":"<div>The endothelium is a key site of injury from reactive oxygen species that can potentially be protected by the antioxidant enzymes superoxide dismutase and catalase. Large proteins, such as superoxide dismutase and catalase, do not readily penetrate cell membranes, which limits their efficacy in protecting cells from cellular reactions involving both intracellularly and extracellularly generated reactive oxygen species. Two methods are described that promote enzyme delivery to cultured endothelial cells and confer increased resistance to oxidative stress. The first method is to entrap the antioxidant enzymes within liposomes, which then become incorporated by endothelial cells and can increase enzyme specific activities by as much as 44-fold within 2 h. The second method involves covalent conjugation of polyethylene glycol (PEG) to superoxide dismutase and catalase, a technique that increases circulatory half-life and reduces protein immunogenicity. Conjugation of PEG to superoxide dismutase and catalase increased cellular-specific activities of these enzymes in cultured endothelial cells (but at a slower rate than for liposome entrapped enzymes) and rendered these cells more resistant to oxidative stress. Both liposome-mediated delivery and PEG conjugation offer an additional benefit over native superoxide dismutase and catalase because they can increase cellular antioxidant activities in a manner that can provide protection from both intracellular and extracellular superoxide and hydrogen peroxide.</div>","PeriodicalId":77737,"journal":{"name":"Journal of free radicals in biology & medicine","volume":"2 5","pages":"Pages 359-365"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0748-5514(86)80036-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14719406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 44

High-affinity iron binding by xanthine oxidase 黄嘌呤氧化酶高亲和铁结合

Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80041-1

Glenn F. Vile, Christine C. Winterbourn

引用次数: 5

Announcements and calendar 公告和日历

Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80075-7

引用次数: 0

Editor's note 编者按

Journal of free radicals in biology & medicine Pub Date : 1986-01-01 DOI: 10.1016/S0748-5514(86)80003-4

引用次数: 0