Glutathione plays different roles in the induction of the cytotoxic effects of inorganic and organic arsenic compounds in cultured BALB/c 3T3 cells

The cytotoxicity of arsenic compounds towards BALB/c 3T3 cells in culture was investigated, together with the role of glutathione (GSH) in the induction of the cytotoxic effects. The rank order of cytotoxicity was as follows: arsenite (As³⁺)>arsenate (As⁵⁺)>dimethylarsinic acid (DMAA)>methylarsonic acid (MAA)>trimethylarsine oxide (TMAO). Arsenobetaine, arsenocholine and the tetramethylarsonium ion were less toxic. Depletion of GSH enhanced the cytotoxic effects of As³⁺, As⁵⁺, MAA and TMAO, while the cytotoxicity of DMAA was markedly reduced by depletion of GSH. These results suggest that GSH plays a role in protecting the cells against the toxic effects of As³⁺, As⁵⁺, MAA and TMAO while it is involved in the induction of the cytotoxic effects of DMAA.     

谷胱甘肽过氧化物酶模拟物6-CySeCD对过氧化氢诱导小鼠成纤维细胞损伤的保护作用

考察不同剂量的H2O2作用于小鼠成纤维细胞(NIH3T3)后,细胞脂质过氧化、存活率、DNA片段化的变化情况,并研究谷胱甘肽过氧化物酶(GPX)的模拟物6A,6B-环己胺-6A′,6B′-硒桥联-β-CD(6-CySeCD)抗H2O2诱导小鼠成纤维细胞损伤的能力.结果表明:H2O2对NIH3T3细胞有严重损伤;6-CySeCD能有效保护细胞,防止紫外线引起的损伤.     

荧光光度法测定大豆提取液中还原型谷胱甘肽

在Cohn的荧光分光光度法的基础上,不加去蛋白试剂,用365nm作为激光发波长,探讨了用荧光光度法测定大豆提取液中的还原型谷胱甘肽的方法,确定了最佳测定条件,该方法用于测定大豆提取液中谷胱甘肽的含量,取得了满意结果。     

甲醛对运动大鼠脑组织的氧化损伤及刺五加保护作用的实验研究

目的：通过实验观察甲醛对运动大鼠脑组织抗氧化系统的影响及服用刺五加后的情况,探讨甲醛对运动大鼠的神经毒性及刺五加的保护作用.方法：采用人为模拟不同程度甲醛染毒环境进行动式染毒,甲醛剂量分别为0.8mg/m3,2.4mg/m3.每天染毒30min,每周6次,连续4周,刺五加的灌胃剂量为104.17mg/kg,测定运动大鼠脑组织的超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）、过氧化氢酶（CAT）的活力和丙二醛（MDA）的含量.结果：染毒组与对照组相比,2.4mg/m3剂量染毒组大鼠脑组织CAT、GSH-PX、SOD活性明显低于对照组（P＜0.01）,MDA含量明显高于对照组（P＜0.01）.服药染毒运动组与染毒运动组相比,0.8mg/m3剂量染毒服药组大鼠脑组织CAT、GSH-PX、SOD活性明显高于染毒运动组（P＜0.01）,MDA含量明显低于染毒运动组（P＜0.01）.结论：甲醛可以降低染毒大鼠脑组织抗氧化酶的活性,造成脑组织氧化性损伤,而灌服中药刺五加可以有效缓解其毒性.     

Physiological and nutritional importance of selenium

Summary The essential trace element selenium has recently attracted attention because of its potentialities in the maintenance of human health. Selenium forms part of the active site of the peroxide-destroying enzyme glutathione peroxidase, and it also has other functions, for example in biotransformation, detoxification and the immune response. Functional and clinical consequences of selenium deficiency states have been described, and the selenium requirement, which is influenced by the usual selenium exposure, has been discussed. Wide variations have been found in selenium status in different parts of the world, and populations or groups of patients exposed to marginal deficiency are more numerous than was previously thought.Current research activities in the field of human medicine and nutrition are devoted to the possibilities of using selenium for the prevention or treatment of degenerative or free radical diseases such as neurological disorders, inflammatory diseases or cancer. Pharmacological selenium doses are also recommended as an adjuvant in some treatments.     

Primary Structural Characterization of Phospholipid Hydroperoxide Glutathione Peroxidase

IntroductionBoth physico-chemical properties and functions ofproteins are based on their primary structure.Theoretical analysis of the primary structure ofproteins will give the structural characteristics ofthe same kind of proteins and provide ideas forfurther experimental research. More than 2 0native or deduced phospholipid hydroperoxideglutathione peroxidase (PHGPX) proteins werefound;three of which were cloned from rice,momordica and radishes in our laboratory[1 ,2 ] .There is a need to…     

氧化砷对MR2细胞耐药分子表达的影响

探讨三氧化二砷(As2O3)对肿瘤耐药分子的作用.以耐全反式维甲酸(ATRA)早幼粒自血病细胞株MR2为研究对象,以非耐药急性早幼粒白血病细胞株NB4为对照组,用免疫组化法观察P-糖蛋白(Pgp)、谷胱甘肽S转移酶(GST)的表达.MR2细胞Pgp表达(30％～40％)较NB4细胞(10％～20％)明显增强(P<0.001),MR2细胞GSTπ表达(60.4±4.0)～(66.5±4.4),较NB4细胞(28.3±5.6)～(31.2±5.1)明显增强(P<0.05).0.5～2.0 μmol/L As2O3能显著降低MR2细胞Pgp、GSTπ表达,而对GSTα、GSTμ无影响.Pgp、GSTπ表达的下调,可能是As2O3克服耐药的敏感性指标,而GSTα、GSTμ则否.全反式维甲酸(ATRA)可能是Pgp转运底物和GSTπ催化作用底物.     

基于谷胱甘肽刻蚀核壳Au@MnO2纳米粒子比色检测谷胱甘肽

谷胱甘肽(GSH)在控制细胞氧化还原状态中起着至关重要的作用，其在人体内浓度异常与许多疾病密切相关，因此，检测GSH具有重要意义.在磷酸缓冲盐溶液(pH=6.2)中，核壳型Au@MnO₂纳米粒子的外壳MnO₂被GSH刻蚀，使体系溶液颜色改变(浅绿→浅红)，吸光度降低.基于此原理，通过测量Au@MnO₂体系的比色信号随GSH浓度的变化，可以实现GSH的检测.在优化的条件下，Au@MnO₂传感体系检测GSH的线性范围为2nmol/L～0.1 mmol/L，检出限为1.62 nmol/L(S/N=3).该方法操作简单、灵敏度高、结果可视化，该传感体系对检测GSH具有很好的选择性，并可用于人血清样品中GSH的检测.     

关于谷胱甘肽硫转移酶M1和T1基因多态性与疾病风险关系Meta分析的中文文献的文献计量学分析

通过《中国知网》的"期刊""特色期刊""博士论文""硕士论文"和"国内会议"五大子库,对谷胱甘肽硫转移酶M1和T1(GSTM1、GSTT1)基因多态性与疾病风险关系Meta分析的文献进行了跨库检索,经筛选,得到40篇以中文发表的Meta分析文献,并用文献计量方法对其发表年度、来源子数据库、学科、发表期刊、作者、机构、基金等进行了统计分析,以期对关于GSTM1、GSTT1基因多态性与疾病风险关系Meta分析的国内文献的发展趋势有更全面的认识.     

Seasonal variation of gut Cyanophyta contents and liver GST expression of mud carp （Cirrhina molitorella） and Nile tilapia （Oreochromis niloticus） in the tropical Xiangang Reservoir （Huizhou, China）

Liver glutathione S-transferase(GST) plays a major role in the detoxification of microcystins(MCs) via conjugation to glutathione(GSH).We evaluated the relationship between seasonal variation in fish gut contents and the expression of GST isoforms in mud carp(Cirrhina molitorella) and Nile tilapia(Oreochromis niloticus).We quantified the abundance and diversity of plankton in the water column and foregut of mud carp and Nile tilapia in the tropical Xiangang Reservoir between October 2007 and July 2008.The mRNA expression of 7 liver GST isoforms was determined by real-time RT-PCR.The gut contents of both species were dependent on the amount and type of phytoplankton and zooplankton in the water.The expression of liver GST genes in Nile tilapia and mud carp was positively and negatively correlated,respectively,with the abundance of toxic cyanobacteria in the fore-gut.The expression of liver GST mRNA was correlated to the abundance of toxic cyanobacteria in the gut contents of both species,suggesting that mRNA expression of GST isoforms could be used as a biomarker in Nile tilapia and mud carp to monitor cyanobacteria blooms in reservoirs.