燕麦劣变种子吸胀过程中线粒体AsA-GSH循环的生理响应

为探究种胚线粒体抗坏血酸-谷胱甘肽(ascorbate-glutathione,AsA-GSH)循环响应老化的抗氧化作用机制,本试验通过控制劣变处理获得高活力和中活力燕麦(AvenaSativa.L)种子,以未老化种子作为对照,研究了吸胀过程中的发芽特性、种胚线粒体活性氧(reactive oxygen species...     

氧自由基对动物消化道损伤及干预研究进展

近年来的研究结果表明:氧自由基与消化道疾病的发生有关,作者综述了氧化应激状态下氧自由基对动物消化道损伤机理研究现状和发展趋势,为该领域研究工作的开展提供参考。     

硫化氢对镉胁迫下小麦幼苗的生长及生理指标的影响

为了解硫化氢(H_2S)对Cd~(2+)胁迫下小麦幼苗生长的缓解机理,以小麦品种苏科麦一号为材料,在水培条件下,测定外源H_2S(供体为NaHS溶液)预处理对Cd~(2+)胁迫下(CdCl_2浓度为50μmol·L~(-1))小麦幼苗生长和生理指标的影响。结果显示,外源H_2S预处理显著提高Cd~(2+)胁迫下小麦幼苗的株高、地上部生物量、非蛋白巯基化合物含量、叶片光合色素含量、净光合速率、叶绿素荧光相关指标(PSⅡ的光合性能指数、单位激发态面积吸收的能量、用于还原Q_A和用于电子传递的能量、非光化学淬灭)和根部Cd含量;显著降低小麦叶片中的过氧化物质(丙二醛、过氧化氢和超氧根阴离子)含量及地上部分Cd含量和Cd转运系数。综上所述,外源H_2S预处理可清除Cd~(2+)胁迫小麦幼苗叶片中的活性氧自由基,减少其对光合色素分子的破坏,降低膜脂过氧化程度,保护光合电子传递系统,增加热耗散,提高光合能力,缓解Cd~(2+)对小麦幼苗生长的抑制,以50μmol·L~(-1)的NaHS效果最好。     

Induction of disease resistance and ROS metabolism in navel oranges by chitosan

The objective of this work was to evaluate how disease resistance and reactive oxygen species (ROS) metabolism in harvested navel oranges (Citrus sinensis L. Osbeck) may be affected by chitosan. Fresh navel oranges were treated with 2% chitosan or 0.5% glacial acetic acid (control) solution for 1 min, and some were inoculated with Penicillium italicum and Penicillium digitatum. Then, the fruit were stored at 20 °C and 85–95% RH. Treatment with 2% chitosan significantly reduced the disease incidence and the lesion diameter compared with control fruit. This treatment effectively enhanced the activities of peroxidase (POD) and superoxide dismutase (SOD), and levels of glutathione (GSH) and hydrogen peroxide (H₂O₂), inhibited the activities of catalase (CAT) and the decreases of ascorbate (AsA) content during navel orange fruits storage. Ascorbate peroxidase (APX) activity in the navel orange fruit was induced slightly by the chitosan treatment during 14–21 days storage. However, glutathione reductase (GR) activity in the fruit was not enhanced by the chitosan treatment. These results indicated that chitosan treatment could induce the navel orange fruit disease resistance by regulating the H₂O₂ levels, antioxidant enzyme and ascorbate–glutathione cycle.     

活性氧抑制剂对绞股蓝皂苷抑癌作用的影响

【目的】研究活性氧清除剂N-乙酰半胱氨酸(NAC)对绞股蓝皂苷(Gypenosides,Gyp)作用下人结直肠癌SW620细胞生长抑制的作用。【方法】采用MTT法检测NAC对Gyp作用下SW620细胞增殖的影响;采用流式细胞仪观察NAC对Gyp处理的SW620细胞的线粒体膜电位、DNA片段生成及细胞凋亡的影响。【结果】NAC可以对抗Gyp对SW620细胞的增殖抑制;可解除Gyp诱导SW620细胞凋亡过程中引起的线粒体膜电位降低,从而抑制DNA片段生成的增加,进而抑制Gyp诱导的SW620细胞凋亡。【结论】Gyp在诱导SW620细胞凋亡的过程中启动了关键因子活性氧,从而导致线粒体膜电位下降、DNA损伤,并最终诱导细胞凋亡;活性氧抑制剂可以削弱这种影响。     

活性氧对猪卵母细胞SUMO-1表达及其质量的影响

本研究旨在调查活性氧过氧化氢（hydrogen peroxide,H₂O₂）对猪卵母细胞体外成熟（in vitro maturation,IVM）过程中蛋白质类泛素SUMO-1表达及精-卵结合能力的影响。试验分为0（control）、10、50、75和100 μg/mL H₂O₂处理组。利用Western blotting、流式细胞术、实时荧光定量PCR、Hoechst染色等方法检测猪卵母细胞体外成熟、蛋白质类泛素SUMO-1含量、细胞活力、凋亡基因mRNA表达、透明带（zona pellucid,ZP）溶解度和精子-卵母细胞结合的表达。结果表明,75 μg/mL H₂O₂组与对照组、10和50 μg/mL H₂O₂组比较卵母细胞体外成熟率及细胞活力显著降低;75 μg/mL H₂O₂组与其他H₂O₂组相比ZP溶解时间显著延长,并减少了精子黏附在成熟卵母细胞透明带上的数量（P<0.05）。在77和18 ku处出现SUMO-1蛋白标记,75 μg/mL H₂O₂组与对照组、10和50 μg/mL H₂O₂组比较SUMO-1蛋白含量显著降低（P<0.05）。75 μg/mL H₂O₂与对照组、10和50 μg/mL H₂O₂组比较显著下调了Bcl-2基因,而Caspase-3基因表达与对照组和10 μg/mL H₂O₂组比较显著升高（P<0.05）,50 μg/mL H₂O₂与对照组和10 μg/mL H₂O₂组相比显著上调了Bax基因水平（P<0.05）。综上所述,H₂O₂能调控猪卵母细胞体外成熟过程中类泛素化水平以及精-卵结合能力。     

抗氧化剂对家畜胚胎体外发育影响的研究进展

现在研究普遍认为活性氧自由基是导致胚胎体外发育阻滞的主要原因。本文主要综述了不同抗氧化剂对牛胚胎体外发育的影响,并分析其作用机制。     

植物叶绿体SOD的转录调控与功能研究进展

对叶绿体SOD的遗传分类、转录调控过程以及SOD在叶绿体中的功能进行综述分析.叶绿体SOD的转录表达与铜分子伴侣(CCS)及Cu离子浓度密切相关.不同Cu离子浓度能够使不同类型SOD在叶绿体中选择性表达;在植物叶绿体中,SOD还可以进行电子传递、调节电子转移以及保护光合作用等.研究SOD缺失突变体及超表达对植物的影响,对分析SOD的功能具有重要意义.     

Administration of a herbal immunoregulation mixture enhances some immune parameters in carp (<Emphasis Type="Italic">Cyprinus carpio</Emphasis>)

The herbal immunoregulation mixture (HIRM) were extracts of several traditional Chinese medicines (TCMs): Astragalus membranaceus (from the root and stem), Polygonum multiflorum Thunb. (from the root), Isatis tinctoria L. (from the root), Glycyrrhiza glabra (from the stem). Immune parameters, which included macrophage phagocytic activity, macrophage reactive oxygen species (ROS), activity of serum lysozyme, nitric oxide synthetase (NOS) and superoxide dismutase (SOD), levels of total serum protein, globulin, albumin, triglyceride and cholesterol, were determined in carp that had been fed diets containing HIRM at 0.5% or 1% for 30 days. The results showed that, compared with those in the control group, the diets with 0.5% and 1% HIRM resulted in significant increase in macrophage phagocytic activity, macrophage ROS and the levels of total protein, globulin, albumin and NOS activity in serum (P < 0.05), and no significant difference was found in SOD, lysozyme activities and triglyceride level (P > 0.05). On the other hand, 0.5% HIRM led to evident enhancement of NOS activity and cholesterol level compared to 1% HIRM. These results indicated that HIRM might elevate the function of immunity in carp (Cyprinus carpio).     

Hemocyte characteristics in families of oysters, Crassostrea gigas, selected for differential survival during summer and reared in three sites

High variability among individuals is often encountered when hemocyte characteristics are measured in bivalves. Such variability is suspected to result partly from genetic factors. In this study, hemocyte characteristics of six families of Crassostrea gigas were compared by flow cytometry at one sampling date in October 2001. These families were obtained from a nested, half-sibling cross design, and reared from July to October 2001 at three sites distributed along the French Atlantic coast from north to south: Baie des Veys (Normandy), Rivière d'Auray (Brittany) and Ronce (Marennes-oléron Basin, Poitou Charentes).

Among the 15 measured hemocyte characteristics, production of reactive oxygen species (ROS) of untreated hemocytes (maintained in filtered sterile seawater) and treated hemocytes (zymosan at 20 particles per hemocyte, and with Vibrio sp. S322 at 50 bacteria per hemocyte) was the most notable differences between families. This supports the existence of a genetic basis, at least partly, for the hemocyte characteristics of oysters, and especially for ROS production.

Among the six families analyzed, three have shown high survival during summer (named as “resistant”, mean mortality 5.2%) and three experienced high mortality during summer (named as “susceptible”, 30.6% mean mortality). Families showing high or low survival to summer mortality had similar hemocyte characteristics, regardless of the environmental conditions or reproductive state. Resistant families were observed to have higher total hemocyte counts and lower production of ROS than susceptible families. Moreover, ROS production of hemocytes from susceptible families was diminished significantly more by pathogenic Vibrio than that of resistant families. However, this study demonstrates also that rearing site strongly affected the hemocyte characteristics of all families of oysters, most notably hemocyte concentration and morphology (size and granularity), production of reactive oxygen species (ROS), and susceptibility to the cytotoxic activity of the pathogenic Vibrio sp. S322 (50 bacteria/hemocyte). Food availability and reproductive state are the most probable explanations for the site differences observed. Finally, it appeared difficult to link oyster survival during summer mortality to hemocyte profiles evaluated at one sampling date; other relevant indicators would probably help explaining oyster survival during summer mortality events.