镉胁迫对萝卜幼苗活性氧产生、脂质过氧化和抗氧化酶活性的影响

镉胁迫使萝卜幼苗超氧阴离子(O2)、过氧化氢(H2O2)和丙二醛(MDA)含量增加;随着镉浓度提高,超氧化物歧化酶(SOD)活性首先明显上升,然后逐渐下降,甚至低于对照;叶片过氧化氢酶(CAT)活性明显增加,根系CAT活性则减少;根系以及较高浓度镉处理后期叶片的谷胱甘肽还原酶(GR)活性均显著增加.由此推测:在胁迫初期可能主要由SOD和CAT发挥抗氧化作用,而在胁迫后期由于抗坏血酸-谷胱甘肽(AsA-GsH)循环途径的激活,还原型谷胱甘肽和植物络合素含量的提高可能在清除活性氧或者直接螯合镉中起作用.     

Thyroid Hormone Influences Antioxidant Defense System in Adult Rat Brain

The objective of the current study was to find out whether thyroid hormone influences antioxidant defense parameters of rat brain. Several oxidative stress and antioxidant defense parameters of mitochondrial (MF) and post-mitochondrial (PMF) fractions of cerebral cortex (CC) of adult rats were compared among euthyroid (control), hypothyroid [6-n-propylthiouracil (PTU)-challenged], and hyperthyroid (T3-treatment to PTU-challenged rats) states. Oxidative stress parameters, such as thiobarbituric acid-reactive substances (TBA-RS) and protein carbonyl content (PC), in MF declined following PTU challenge in comparison to euthyroid rats. On the other hand, when PTU-challenged rats were treated with T3, a significant increase in the level of oxidative stress parameters in MF was recorded. Hydrogen peroxide content of MF as well as PMF of CC was elevated by PTU-challenge and brought to normal level by subsequent treatment of T3. Although mitochondrial glutathione (reduced or oxidized) status did not change following PTU challenge, a significant reduction in oxidized glutathione (GSSG) level was noticed in PMF following the treatment. T3 administration to PTU-challenged rats had no effect on mitochondrial glutathione status. Total and CN-resistant superoxide dismutase (SOD) activities in MF of CC augmented following PTU challenge. CN-resistant SOD activity did not change when PTU-challenged rats were treated with T3. Although CN-sensitive SOD activity of PMF remained unaltered in response to PTU challenge, its activity increased when PTU-challenged rats were treated with T3. Catalase activity in PMF of CC of PTU-challenged rats increased, whereas the activity was decreased when hypothyroid rats were treated with T3. Similarly, total and Se-dependent glutathione peroxidase (GPx) activities of MF increased following PTU challenge and reduced following administration of T3. Se-independent GPx activity of MF and PMF and glutathione reductase activity of PMF decreased following PTU challenge and did not change further when rats were treated with T3. On the other hand, glutathione S-transferase activity of MF and PMF of CC did not change following PTU challenge but decreased below detectable level following T3 treatment. Results of the current investigation suggest that antioxidant defense parameters of adult rat brain are considerably influenced by thyroid states of the body.     

外源水杨酸对高温胁迫下葡萄几种抗氧化酶活性和抗氧化物含量的影响

本文以二年生‘克瑞森’无核葡萄为材料,探明外源水杨酸（SA）对高温胁迫下葡萄体内几种酶活性和抗氧化物质含量的影响及其在抗高温胁迫中的作用。实验结果表明,与对照相比,外源SA可以促进高温胁迫下葡萄叶片内ASA和GSH含量的积累,维持较高的APX、GR、SOD、POD和CAT活性。外源SA可能通过提高高温胁迫下葡萄体内抗氧化水平,削弱了高温胁迫对葡萄植株的氧化胁迫伤害作用。     

Interactions Between Chronic Stress and Chronic Consumption of Caffeine on the Enzymatic Antioxidant System

We studied the effect of chronic caffeine on parameters related to oxidative stress in different brain regions of stressed and non-stressed rats. Wistar rats were divided into three groups: control (receiving water), caffeine 0.3 g/L and caffeine 1.0 g/L (in the drinking water). These groups were subdivided into non-stressed and stressed (repeated restraint stress during 40 days). Lipid peroxide levels and the total radical-trapping potential were assessed, as well as antioxidant enzyme activities superoxide dismutase, gluthatione peroxidase, and catalase in hippocampus, striatum and cerebral cortex. Results showed interactions between stress and caffeine, especially in the cerebral cortex, since caffeine increased the activity of some antioxidant enzymes, but not in stressed animals. We concluded that chronic administration of caffeine led, in some cases, to increased activity of antioxidant enzymes. However, these effects were not observed in the stressed animals.     

Exogenous Selenium Mitigates Salt Stress in Soybean by Improving Growth,Physiology, Glutathione Homeostasis and Antioxidant Defense

The mechanism of selenium (Se)-induced salt tolerance was studied in moderately sensitive soybean (Glycine max L.) plants. To execute this view, soybean plants were imposed with salt stress (EC 6 dS m⁻¹ ) applying NaCl. In other treatments, Se (0, 25, 50 and 75 µM Na₂SeO₄) was sprayed as co-application with that level of salt stress. Plant height, stem diameter, leaf area, SPAD value decreased noticeably under salt stress. Altered proline (Pro) level, together with decreased leaf relative water content (RWC) was observed in salt-affected plants. Salt stress resulted in brutal oxidative damage and increased the content of H₂O₂, MDA level and electrolyte leakage. Exogenous Se spray alleviated oxidative damage through boosting up the antioxidant defense system by increasing the activity of antioxidant enzymes such as catalase (CAT), peroxidase (POD) and glutathione reductase (GR), as well as by improving non-enzymatic antioxidants like glutathione (GSH) and GSH/glutathione disulfide (GSSG). The upregulated antioxidant defense system, restored Pro and leaf RWC, higher SPAD value conferred better growth and development in Se-sprayed salt-affected soybean plants which altogether put forth for the progressive yield contributing parameters and finally, seed yield. Among different doses of Se, soybean plants sprayed with 50 µM Na₂SeO₄ showed better salt tolerance.     

急性低温对黑鲷抗氧化酶活性和 热休克蛋白含量的影响

为探究急性低温胁迫对黑鲷（Acanthopagrus schlegelii）生理机能的影响,以1龄黑鲷作为实验鱼,以15 ℃为对照组,设置10 ℃和5 ℃作为低温胁迫组,处理24 h后再转入15 ℃的水体中进行恢复实验,测定不同温度、不同时间点下1龄黑鲷肝的抗氧化酶活性以及热休克蛋白（Hsp）含量的变化。研究结果显示,低温胁迫实验中,低温处理组（10 ℃和5 ℃）在急性低温胁迫的24 h内,超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-PX）活性和热休克蛋白含量均呈现先上升后下降的趋势。10 ℃处理组上述三种抗氧化酶活性皆在12 h达到最大值,超氧化物歧化酶、过氧化氢酶活性24 h恢复到对照水平,而谷胱甘肽过氧化物酶在18 h已经恢复到正常水平;在5 ℃处理组,超氧化物歧化酶和过氧化氢酶活性在6 h达到最大值,谷胱甘肽过氧化物酶在18 h达到最大值,且在24 h都仍与对照组有极显著差异,超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶活性分别在恢复实验的12 h、12 h和6 h恢复到对照组水平。10 ℃和5 ℃两个处理组的热休克蛋白含量皆在胁迫18 h达到最大,10 ℃处理组在24 h恢复到正常水平,但5 ℃处理组的热休克蛋白含量直到恢复实验结束仍与对照组存在差异。本实验结果表明,急性低温胁迫对超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶和热休克蛋白具有显著影响,其均呈现有规律的变化趋势,说明上述酶和蛋白参与了黑鲷的低温胁迫应答过程,通过协同调节黑鲷的生理机能使其适应环境变化,减少急性低温对鱼体的损伤并使其能够在环境骤变情况下存活下来。只有在自我调节范围内,黑鲷随着胁迫时间的延长,其体内才能够建立新的生理平衡来适应低温,因此在黑鲷养殖过程中,应当注意水温不宜低于5 ℃,水温过低时,应尽快将其移入室内,避免水温骤降对鱼体造成损伤。     

Primaquine Alters Antioxidant Enzyme Profiles in Rat Liver and Kidney

The effects of primaquine treatment on antioxidant enzyme activities were investigated in rat liver and kidney. Male Sprague-Dawley rats were treated with 0.21 mg/kg daily for two weeks (chronic treatment) or a single dose at 0.21 or 0.63 mg/kg. Antioxidant enzyme activities were determined in liver and kidney cytosolic fractions whereas glutathione (GSH) and malondialdehyde (MDA) levels were determined in tissue samples. Results for the liver showed increases in cytosolic superoxide dismutase (SOD) and glutathione peroxidase (GPX) enzymatic activities after chronic primaquine treatment. Levels of MDA, a marker for lipid peroxidation, were also increased by more than 50% indicating enhanced oxidative damage in the liver. In the single dose study, 0.63 mg/kg primaquine caused a more than 100% increase in liver SOD and a 36% increase in NAD (P) H: quinone oxidoreductase (NQOR) activities. Results for the kidney, however, showed fewer primaquine-induced changes in antioxidant enzyme activities when compared to the liver in both the chronic and single dose studies. Overall, our results indicate that primaquine treatment causes an oxidative stress in the two rat organs. These results are consistent with the known pro-oxidant effects of primaquine in vivo, and supplement current knowledge on the effects of antimalarial drugs on various enzyme systems.     

In Vivo Esr Studies of Antioxidant Activity on Free Radical Reaction in Living Mice Under Oxidative Stress

In vivo antioxidant activity seems to be quite complicate due to multiple interaction with biomaterials and differs from results by in vitro experiments. In vivo estimation of antioxidant activity is performed by measuring TBA reactive substances in blood or hydrocarbon gases in breath, but these systems do not measure free radical reaction but the final products of oxidative reaction. In the present study, we applied in vivo ESR to evaluate antioxidant activity by monitoring the redox reaction of nitroxide radical and clearly found that the nitroxide is very susceptible to oxidative stress in vivo and quite useful to evaluate antioxidant activity non-invasively.     

烟草愈伤组织在热胁迫过程中活性氧与抗氰呼吸变化的关系

烟草愈伤组织在 0～ 14h高温 (4 0℃ )胁迫期间 ,其体内的O- ·2 和H2 O2 迅速积累 ,分别在 2和 6h左右达到极大值。同时清除它们的酶SOD和CAT活性迅速上升 ,极大值的分布位置分别为 2和 10h左右 ,而胁迫期间的抗氰呼吸比未胁迫 (0h)时显著地下降 ,但在胁迫期间抗氰呼吸于 6h左右出现一峰值 ;用外源H2 O2 和O- ·2 及清除它们的酶的抑制剂AT和DCC分别处理愈伤组织 ,发现抗氰呼吸明显地加强。推测交替氧化酶可能同抗氧化酶如SOD和CAT一样参与了活性氧的清除 ,提出活性氧含量的变化可能是导致热胁迫过程中抗氰呼吸变化的主要原因之一。     

转GmTMT2a基因玉米抗旱功能分析

生育酚具有很强的抗氧化功能,其中α-生育酚是最有效的组分。研究了α-生育酚含量提高的转GmTMT2a基因植株（TP）和野生型植株（WT）在干旱条件下的响应差异。结果表明,TP植株和WT植株中H2O2 含量均有所增加,但TP植株中累积了更少的H2O2;抗氧化酶类SOD、POD和CAT的酶活测定结果表明,CAT酶活性在TP植株中的增幅最大;抗旱相关基因表达分析结果显示,P5CS和TPS在TP植株中的表达显著上调。推测转GmTMT2a基因后,提高了CAT的酶活以及P5CS和TPS的表达量,进而增强了植株的抗旱性。     

Oxidative Stress and Antioxidant Responses in Young Leaves of Mulberry Plants Grown Under Nitrogen, Phosphorus or Potassium Deficiency

The aim of this study was to associate the generation of reactive oxygen species （ROS） with Induced antloxidant responses and disturbed cellular redox environment in the nitrogen-（N）, phosphorus-（P）, or potassium-（K） deftcient mulberry （Morus alba L. var. Kanva-2） plants. The indicators of oxidative stress and cellular redox environment and antioxldant defense-related parameters were analyzed. Oeficlency of N, P or K suppressed growth, accelerated senescence, and decreased concentrations of chloroplastic pigments and glutathione. Lipid peroxidation and activities of superoxide dismutase, ascorbate peroxidase and glutathione reductase were also increased in these N, P, or K deprived plants. Concentration of hydrogen peroxide Increased in plants deficient in N or P. Oeficlency of N or P particularly altered the cellular redox environment as indicated by changes in the redox couples, namely ascorbic acid/total ascorbate decreased in P-, glutathione sulfydryl/total glutathione decreased in N-, and Increased in P-deficient plants. Activity staining of native gels for superoxide dismutase revealed Increased activity as Indicated by Increased intensity of bands, and induction of few new isoforms in P- and K-deficient plants. Oifferences in the patterns of superoxide dismutase isoforms and redox status （ascorbic acid/total ascorbate and glutathlone sulfydryl/total glutathione） Indicate that N-, P-, or K-deficiency altered antioxidant responses to varying extents in mulberry plants.     

Salt-Induced Changes in Physio-Biochemical and Antioxidant Defense System in Mustard Genotypes

Salinity stress is a major factor limiting plant growth and productivity of many crops including oilseed. The present study investigated the identification of salt tolerant mustard genotypes and better understanding the mechanism of salinity tolerance. Salt stresses significantly reduced relative water content (RWC), chlorophyll (Chl) content, K⁺ and K⁺ /Na⁺ ratio, photosynthetic rate (P_N), transpiration rate (Tr), stomatal conductance (gs), intercellular CO₂ concentration (Ci) and increased the levels of proline (Pro) and lipid peroxidation (MDA) contents, Na⁺ , superoxide (O₂^•− ) and hydrogen peroxide (H₂O₂) in both tolerant and sensitive mustard genotypes. The tolerant genotypes maintained higher Pro and lower MDA content than the salt sensitive genotypes under stress condition. The activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), glutathione peroxidase (GPX), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR) were increased with increasing salinity in salt tolerant genotypes, BJ-1603, BARI Sarisha-11 and BARI Sarisha-16, but the activities were unchanged in salt sensitive genotype, BARI Sarisha-14. Besides, the increment of ascorbate peroxidase (APX) activity was higher in salt sensitive genotype as compared to tolerant ones. However, the activities of glutathione reductase (GR) and glutathione S-transferase (GST) were increased sharply at stress conditions in tolerant genotypes as compared to sensitive genotype. Higher accumulation of Pro along with improved physiological and biochemical parameters as well as reduced oxidative damage by up-regulation of antioxidant defense system are the mechanisms of salt tolerance in selected mustard genotypes, BJ-1603 and BARI Sarisha-16.     

Investigation of Cadmium-Induced Genotoxicity and Oxidative Stress Response in Indian Major Carp,Labeo rohita

We investigated genotoxicity and oxidative stress in the gills of Labeo rohita exposed to 33.6, 67.1, and 100.6 mg L^–1of cadmium chloride at 96 h. Genotoxicity was assessed using single cell gel electrophoresis whereas oxidative stress was monitored through lipid peroxidation induction and antioxidant response parameters, namely reduced glutathione (GSH), glutathione peroxidase, glutathione-S-transferase, superoxide dismutase, and catalase (CAT) activities. Significant (p < .05) effect of both concentration and time of exposure was observed on the extent of DNA damage in treated fish. Similarly, malondialdehyde content, level of GSH, and activities of antioxidant enzymes were significantly elevated in treated groups, except CAT. The increased DNA damage and lipid peroxidation (LPO) content along with fluctuation in antioxidant defense system in fish indicated the interaction of cadmium (Cd) with DNA repair processes and production of reactive oxygen species. Thus, Cd is liable for induction of LPO, alteration of antioxidant defenses, and DNA damage in gills of L. rohita.     

Effect of Cadmium Ions on Antioxidant Defense System in Sunflower Cotyledons

Sunflower (Helianthus annuus L.) seeds were germinated and grown in the presence of 50, 100 and 200 μM CdCl₂. The lower concentration (50 μM) of Cd² ions produced slight decrease in reduced glutathione (GSH) content and overall increase (except superoxide dismutase) in antioxidant enzyme activities, and in H₂O₂ concentration. Chlorophyll content, lipid peroxidation and protein oxidation were not affected under 50 μM CdCl₂. GSH content was diminished under 100 and 200 μM CdCl₂, and except for superoxide dismutase, which activity remained unaltered, overall decreases in the antioxidant enzyme activities (catalase, ascorbate peroxidase, dehydroascorbate peroxidase, glutathione reductase) and in guaiacol peroxidase were observed. These Cd² concentrations caused a decrease in chlorophyll content as well as an increase in lipid peroxidation, protein oxidation and H₂O₂ concentration. All the observed effects were more evident with the highest concentration of cadmium chloride used. This revised version was published online in July 2006 with corrections to the Cover Date.     

Magnitude of Hyperoxic Stress and Degree of Lung Maturity Determine the Nature of Pulmonary Antioxidant Response in the Guinea Pig

The ability of the immature lung to induce antioxidant defences in response to hyperoxic stress was examined. Preterm guinea pigs (65 days gestation, term = 68 d) were exposed to either 21+ O2, 85+ O2 or 95+ O2 for 72 hours. Exposure to 85+ O2 increased lung catalase, glutathione peroxidase and manganese superoxide dismutase activities in comparison to air controls. Exposure to 95+ O2 resulted only in an increase in glutathione peroxidase activity. Bronchoalveolar lavage fluid GSH concentration was increased by a similar amount by both exposure regimes, while lung copper/zinc superoxide dismutase activity was unchanged by either treatment. Comparison of the antioxidant response of term and preterm animals exposed to 85+ O2 for 72 hours indicated a greater response in the lung of the preterm animals. Manganese superoxide dismutase activity was elevated in both term and preterm animals, while catalase and glutathione peroxidase activities were elevated only in preterm animals. The extent of microvascular permeability as indicated by bronchoalveolar lavage fluid protein concentration, was lower in preterm animals than in term animals. We conclude that the immature lung can respond to hyperoxic stress by antioxidant induction and that the nature of the response is dependent, in part, both on the severity of the stress and on the maturity of the lung.     

Magnitude of Hyperoxic Stress and Degree of Lung Maturity Determine the Nature of Pulmonary Antioxidant Response in the Guinea Pig

The ability of the immature lung to induce antioxidant defences in response to hyperoxic stress was examined. Preterm guinea pigs (65 days gestation, term = 68 d) were exposed to either 21+ O2, 85+ O2 or 95+ O2 for 72 hours. Exposure to 85+ O2 increased lung catalase, glutathione peroxidase and manganese superoxide dismutase activities in comparison to air controls. Exposure to 95+ O2 resulted only in an increase in glutathione peroxidase activity. Bronchoalveolar lavage fluid GSH concentration was increased by a similar amount by both exposure regimes, while lung copper/zinc superoxide dismutase activity was unchanged by either treatment. Comparison of the antioxidant response of term and preterm animals exposed to 85+ O2 for 72 hours indicated a greater response in the lung of the preterm animals. Manganese superoxide dismutase activity was elevated in both term and preterm animals, while catalase and glutathione peroxidase activities were elevated only in preterm animals. The extent of microvascular permeability as indicated by bronchoalveolar lavage fluid protein concentration, was lower in preterm animals than in term animals. We conclude that the immature lung can respond to hyperoxic stress by antioxidant induction and that the nature of the response is dependent, in part, both on the severity of the stress and on the maturity of the lung.     

钙对盐胁迫下小金海棠幼苗生物量及抗氧化系统的影响

本文以1/2Hoagland营养液栽培的小金海棠为试材, 研究70 mmol·L-1的NaCl胁迫下, 钙对小金海棠幼苗生物量、超氧自由基（O2 ）产生速率、丙二醛（MDA）含量、电解质相对渗透率、抗氧化酶（SOD、POD、CAT和APX）活性及可溶性蛋白含量的影响。结果表明, 盐胁迫下, 小金海棠幼苗生物量显著低于对照, 根系和叶片的O2 产生速率、MDA含量、电解质相对渗透率、抗氧化酶活性及可溶性蛋白含量显著高于对照。盐胁迫下, 与不加钙处理相比, 加钙处理显著降低了小金海棠幼苗O2 产生速率、MDA含量及电解质相对渗透率, 显著提高了生物量、抗氧化酶和可溶性蛋白的含量, 10 mmol·L-1 CaCl2处理的效果显著好于30 mmol·L-1处理的。综上可知, 盐胁迫下小金海棠幼苗的生长受到抑制, 外源施钙可以减轻盐胁迫对幼苗造成的伤害, 提高幼苗对盐胁迫的适应能力。     

Oxidative Stress and Heat Shock Protein Induction in Human Cells

Agents which induce heat shock protein synthesis in cultured monolayers of Hela cells such as hyperthermia, ethanol and sodium arsenite can also cause increases in the levels of lipid peroxidation as determined by the formation of TBA-products. The heat induced increases may be diminished by addition to the medium of mannitol or EGTA. These compounds are known to depress heat shock protein synthesis.

Following hyperthermia there is also a decrease in protein synthesis. In vitro studies indicate possible damage to ribosomes, and since the heat induced loss of protein synthetic capacity can be increased by superoxide dismutase inhibitors, and prevented by mannitol, such effects may be linked to the increases observed in lipid peroxidation. It is suggested that a connection exists between lipid peroxidation and heat shock protein gene activation.     

Oxidative Stress and Heat Shock Protein Induction in Human Cells

Agents which induce heat shock protein synthesis in cultured monolayers of Hela cells such as hyperthermia, ethanol and sodium arsenite can also cause increases in the levels of lipid peroxidation as determined by the formation of TBA-products. The heat induced increases may be diminished by addition to the medium of mannitol or EGTA. These compounds are known to depress heat shock protein synthesis.

Following hyperthermia there is also a decrease in protein synthesis. In vitro studies indicate possible damage to ribosomes, and since the heat induced loss of protein synthetic capacity can be increased by superoxide dismutase inhibitors, and prevented by mannitol, such effects may be linked to the increases observed in lipid peroxidation. It is suggested that a connection exists between lipid peroxidation and heat shock protein gene activation.     

光质对烟草叶片生长发育过程中抗氧化系统的影响

以云烟87植株为材料,通过覆盖白、红、黄、蓝、紫色滤膜获得不同光质,于大田条件下研究了光质对烟草叶片生长发育过程中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)、谷胱甘肽过氧化物酶(GPX)、谷胱甘肽还原酶(GR)等抗氧化酶活性,抗氧化剂谷胱甘肽(GSH)和抗坏血酸(AsA)以及丙二醛(MDA)含量的影响.结果表明,在烟草植株第11片叶生长发育的7~70 d内,其抗氧化酶活性和抗氧化物质含量呈现先升高后下降的变化趋势.与白光(对照)相比,黄光诱导烟草叶片SOD、CAT、APX和GR活性升高,以及AsA和GSH含量增加;而红光诱导APX和GR活性上升,以及GSH和AsA含量升高;但紫光却使SOD、CAT、POD、GR和GPX活性下降,GSH和AsA含量降低,而蓝光则使所有抗氧化酶活性和抗氧化物质含量降低.紫光和蓝光处理的烟草叶片中MDA含量较高,而黄光和红光处理的则较低.总体而言,在大田条件下,相对红光和黄光而言,蓝光和紫光处理下的烟草叶片更容易发生光氧化胁迫.