氟害大豆超氧化物歧化酶活性与叶绿素含量及叶片脱落的关系

采用人工HF熏气的方法研究了盆栽大豆 (Glycinemax )超氧化物歧化酶 (SOD)活性与叶绿素含量、乙烯产生量、纤维素酶活性之间的关系。结果表明 :(1)HF通过抑制SOD活性降低了叶绿素的含量 ;(2 )HF对参与叶片脱落的纤维素酶的活性诱导是通过抑制SOD活性进而合成大量乙烯实现的。     

稀土元素在鱼体内脏中的富集及对肝脏中酶活性的影响

以鲫鱼为研究对象,研究了稀土元素（Gd和Y）在鱼体内脏各器官中的富集及其对肝脏过氧化氢酶和超氧化物歧化酶水平的影响。研究结果表明,Y在鱼体各内脏器官中的富集顺序为：肝＞胆＞肾＞卵＞脾;Gd在鱼体各内脏器官中的富集顺序为：卵＞肝＞胆＞脾＞肾。二者在肝脏中的富集值均较高,在实验浓度范围中,稀士元素（Gd,Y）对鱼体肝中过氧化氢酶和超氧化物歧化酶的活性均有明显的抑制作用。     

联苯胺对线粒体抗氧化酶活性及同工酶的影响

不同浓度联苯胺(0.5,1.0,1.5,2.0mg/mL),以体外染毒方式作用于武昌鱼-团头鲂(Megalobrama amblycephala)肝脏线粒体,研究了武昌鱼肝脏线粒体两种主要抗氧化酶[谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶(SOD)]活性的变化,用聚丙烯酰胺凝胶电泳法分析了其同工酶谱.结果显示0.5,1.0mg/mL联苯胺激活GSH-Px, 0.5mg/mL联苯胺激活SOD,而1.5, 2.0mg/mL联苯胺抑制这两种酶的活性;另外,在GSH-Px同工酶谱中呈现出特异性标志酶gsh4.     

No difference in activity of Sod-1 genotypes of Poa annua to short-term treatment of ambient gaseous organic pollution

Our previous studies indicated that genotypes at locus Sod-1 of Poa annua changed clinally along a gradient of gaseous organic pollution. In the present study, we aimed to know whether there were differential responses of activities of different superoxide dismutase （SOD） genotypes to short-term treatment of ambient gaseous organic pollution. Significant bias from Hardy-Weinberg equibrium was observed on locus Sod-1, and no genotype Sod- l-BB was found. Significantly increased activities were observed in most treatments for genotype Sod-1-AA and in one treatment for genotype Sod-1-AB. However, no significant difference in SOD activities was found between the two genotypes. It was interpreted that fitness difference between the two genotypes was small and treatment duration was too short or extent of ambient organic pollution was too low to lead to differential responses. Other environmental factor effects on activities of superoxide dismutases can also explain the results.     

Pesticides and Essential Minerals Modify Endogenous Antioxidants and Cytochrome P450 in Tissues of Rats

Two experiments were conducted in male Sprague Dawley (SD) rats (175–200 g) to determine changes in the activities of endogenous antioxidants superoxide dismutase (SOD), glutathione peroxidase (GPX), cytochrome P450 (ethoxyresorufin deethylase; EROD) and concentrations of glutathione (GSH) in the blood, liver, and small intestinal mucosa (IM). In both experiments, six rats/group were fed diets based on the AIN-93M diet (Control) or the same modified to contain either 500 mg calcium (Low Ca), 7 mg Zn (Low Zn): 2 mg copper (Low Cu), 60 mg zinc (High Zn) or 12 mg copper (High Cu) in the following combination: Control, LCa/LZn, LCa/LZn/LCu, or HZn/HCu, with and without a pesticide mixture containing acephate, endosulfan, and thiram at 25% LD₅₀ for four or two weeks. Pesticides decreased feed intake and weight gain in all groups by 28%. Erythrocyte SOD was higher than control in the HZn/HCu group and in the LCa/LZn/LCu and HZn/HCu groups with pesticide (P# 0.05). Plasma GPX declined by more than 55% in all the groups with and without pesticides compared to the control. The LCa/LZn/LCu and HZn/HCu diets with and without pesticides reduced GPX in the IM by up to 88%, 40%, and 74%, respectively, than the control. Plasma GSH was about 20% higher than the control in most groups with and without pesticides in the diet. Liver and IM GSH were higher than the control in the HZn/HCu group, whereas IM GSH concentrations were lower than the control in the LCa/LZn and LCa/LZn/LCu groups (P#0.05). All three experimental diets with and without pesticides had a significant effect on liver EROD activity (P#0.05). The results indicate that endogenous antioxidants and EROD were independently modified by dietary zinc and copper levels and pesticides.     

Micronuclei Frequency in Lymphocytes and Antioxidants in the Blood of Traditional Limited-Resource Farm Workers Exposed to Pesticides

Chronic low-level exposure to synthetic pesticides is implicated in many health conditions that result from the induction of oxidative stress, including cytogenetic damage. The objective of this study was to assess the risk of genotoxicity using micronuclei (MN) formation in lymphocytes and to determine changes in blood antioxidants superoxide dismutase (SOD) in erythrocytes (E) and glutathione (GSH) in E and plasma (PL) in farm workers for six months during a growing season. Blood and urine samples were collected once a month for six months (June to November 2003) from farm workers (n = 15) and urban unexposed controls (n = 10). Lymphocytes from blood were separated by density gradient centrifugation using Histopaque and cultured using the standard technique. There was no significant difference in the cytokinesis blocked proliferation index (CBPI) of lymphocytes between the farm workers and the control group, but there was a 76% increase in average MN frequency in lymphocytes of the farm worker group (P ≤ 0.05). In addition, MN frequency peaked during August as compared to the other months and the controls (P ≤ 0.05). An 18% decline was observed in the activity of E-SOD in the farm worker group (P ≤ 0.05). GSH in E and PL were similar in both groups. These data suggest that the farm workers may be at a greater risk of developing genotoxicity due to continued exposure to pesticides, especially during the intensive growing season.     

柳树乙醇提取物体外抗氧化活性

通过Fenton反应产生.OH,邻苯三酚自氧化产生O2.-模型,研究了柳树乙醇提取物体外清除自由基的作用。结果显示,柳茎和柳叶乙醇提取物在3.125—50 mg/ml浓度范围内具有清除O2.-的作用。随着浓度升高,其清除作用增大。在浓度达到50mg/ml时,柳茎提取物的清除率为75.62%,柳叶提取物的清除率为88.53%;柳茎乙醇提取物在3.125—25 mg/ml浓度范围内,清除.OH的能力随着其浓度的增加而逐渐增强。当浓度为25mg/ml时,其清除率为60.63%;柳叶提取物在浓度3.125—25mg/ml内清除.OH的作用不明显。当浓度达到50mg/ml时,对羟基自由基的清除率为60.63%。     

ZnO纳米粒子抑制体外小鼠光感受器细胞MnSOD的表达及活性

随着纳米技术的发展,纳米材料在生物医药以及化工中已得到广泛应用。作为一类新型材料,其安全性也日益受到人们的高度关注。为探索氧化锌(ZnO)纳米粒子对小鼠视网膜光感受器细胞的毒性作用,本文通过MTT、荧光染色、流式细胞术、实时荧光定量PCR和酶联免疫吸附试验(ELISA)等技术,分别对经不同浓度ZnO纳米粒子处理的小鼠光感受器细胞活性、活性氧水平、锰超氧化物歧化酶(Mn SOD)的基因和蛋白表达及活性进行了检测。结果表明,ZnO纳米粒子可通过诱导细胞线粒体产生过多的活性氧,降低线粒体膜电位,导致小鼠视网膜光感受器细胞损伤;ZnO纳米粒子能显著减少Mn SOD在mRNA和蛋白质水平的表达,降低Mn SOD活性,加剧氧化应激介导的细胞损伤。因此,氧化应激水平的提高导致了过量的活性氧产生及Mn SOD表达和活性的下降,与ZnO纳米粒子引起的细胞毒性作用有关。     

Sub-chronic oral toxicity of acetamiprid in Wistar rats

Acetamiprid is a neoncotinoid insecticide that acts as an agonist to the nicotinic acetylcholine receptor used as insecticide in crops and to control fleas on dogs and cats. The objectives of this study are (1) to evaluate the sub-chronic toxicity of orally administered acetamiprid, (2) to estimate the tissue residue levels and (3) to assess the reactive oxygen species induction in Wistar rats. Clinical signs of toxicity and changes in the haematological parameters were not observed in the acetamiprid-treated groups. Biochemically, increases in the levels of alanine aminotransferase, aspartate aminotransferase, cholesterol and decreases in body weight, feed consumption, reduced glutathione, catalase, superoxide dismutase, glutathione peroxidase, and AchE were observed. Lipid peroxidation was increased in liver and kidney. Acetamiprid residues persisted in liver, kidney, spleen, muscles, brain, fat and histopathology revealed lesions in the liver. The no observable adverse effect level of acetamiprid was found to be ≤55 mg/kg body weight.     

载铁ACF/Ni阴极电化学体系除藻效能与机制

采用化学浸渍法将Fe@Fe₂O₃纳米线负载在活性炭纤维/泡沫镍上组成Fe@Fe₂O₃/ACF/Ni复合阴极,以钛基铂（Pt/Ti）为阳极,考察载铁量、初始pH值和不同电化学体系对除藻效果的影响,探究无供氧条件下Pt/Ti-Fe@Fe₂O₃/ACF/Ni电化学体系除藻的效能;基于·OH间接检测、铁离子浓度、H₂O₂浓度及pH值的分析和·O₂^-的检测研究Pt/Ti-Fe@Fe₂O₃/ACF/Ni中性电化学体系反应机制.结果表明,当制备阴极阶段投加0.03g FeCl₃×6H₂O,初始藻浓度为0.7×10⁹~0.8×10⁹个/L,电流密度为75mA/cm²,初始pH6.2时,电解60min,该体系除藻率可达到92.3%.在Pt/Ti-Fe@Fe₂O₃/ACF/Ni电化学体系中,Fe@Fe₂O₃/ACF/Ni阴极可通过电化学反应产生大量·OH和·O₂^-,使藻细胞破裂死亡;该体系除藻的主要机理是非均相电Fenton反应.