外源性一氧化氮对大鼠肝脏抗氧化物酶和药物代谢酶活性的影响

用亚硝基铁氰化钠（ＳＮＰ）作为ＮＯ生成前体,以０,１,２,４和８ｍｇ·ｋｇ－１ｉｐ给予大鼠,每日一次,连续５ｄ,来研究外源性ＮＯ对大鼠肝脏细胞色素Ｐ４５０,苯胺羟化酶（ＡＨ）,谷胱甘肽Ｓ－转移酶（ＧＳＴ）等药物代谢酶和过氧化氢酶（Ｃａｔ）,谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）,超氧化物歧化酶（ＳＯＤ）等抗氧化物酶活性以及脂质过氧化的体内影响情况．结果表明外源性ＮＯ能明显降低大鼠肝脏ＳＯＤ,Ｃａｔ,ＡＨ的活性和细胞色素Ｐ４５０的含量（Ｐ＜０．０５）,并且高剂量组还能明显促进脂质过氧化发生（Ｐ＜０．０５）,但对ＧＳＨ－Ｐｘ和ＧＳＴ的活性则无明显影响     

海脉冲营养素抗衰老作用的实验研究

本文报道了海脉冲营养素对老龄大鼠体内过氧化脂质（ＬＰＯ）,脂褐素（ＬＰＦ）的含量和超氧化物歧化酶（ＳＯＤ）,光胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性的影响。给老龄大鼠灌服海脉冲营养６０ｄ,结果表明：血液及肝脏中ＬＰＯ含量明显降低（Ｐ〈０．０５）;ＳＯＤ和ＧＳＨ－Ｐｘ酶活性显著提高（Ｐ〈０．０５）;大脑皮层中ＬＰＦ的生成明显减少（Ｐ〈０．０１）。提示海脉冲营养素具有提高老龄大鼠体内抗氧化酶活性、清除自由基、抑制脂质过氧化的作用。     

外源性一氧化氮对大鼠抗氧化酶活性的影响

本研究利用亚硝基铁氰化钠作为体外一氧化氮（ＮＯ）前体，研究ＮＯ对大鼠肝Ｓ９中超氧化物岐化酶（ＳＯＤ），过氧化氢酶（ＣＡＴ）、谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）等抗氧化物酶的活性及脂质过氧化（ＬＰＯ）的影响。结果表明：外源性ＮＯ能体外抑制ＣＡＴ和ＳＯＤ活性，并能引起明显的ＬＰＯ，但对ＧＳＨ－Ｐｘ的活性无明显影响。     

31例突发聋患者血中LPO、SOD、GSH－Px变化

本实验测定３１例突发聋患者的过氧化脂质（ＬＰＯ）及超氧化物歧化酶（ＳＯＤ）、谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）含量，结果突发聋患者的ＬＰＯ明显高于对照组，ＳＯＤ、ＧＳＨ－Ｐｘ明显低于对照组，提示对细胞有损害作用的ＬＰＯ升高，自由基清除系统酶类ＳＯＤ、ＧＳＨ－Ｐｘ活性减低。     

野菊花水提液抗氧化作用的实验研究

目的：观察野菊花水提液的体内外抗氧化的作用。方法：分别用ＴＢＡ法、ＤＴＮＢ法及紫外分光光度测定脂质过氧化（ＬＰＯ）产物ＭＤＡ的含量、全血谷胱甘肽过氧化物酶（ＧＳＨ－Ｐx）及过氧化氢酶（ＣＡＴ）活力。结果：野菊花水提液体外可抑制大鼠心、脑、肝、肾组织自动ＬＰＯ及由Ｈ２Ｏ２引发的红细胞脂质过氧及溶血;小鼠ｉｇ给药２ｇ／（ｋｇ．ｄ）７ｄ,可显著升高全血ＧＳＨ－Ｐx、ＣＡＴ活力（Ｐ〈０．０５）。结论：野菊     

甘草对老年大鼠CAT,GSH—Px,LPO影响的实验研究

本实验以Ｗｉｓｔａｒ大鼠为研究对象,对大鼠红细胞ＣＡＴ（过氧化氢酶）活性,全血ＧＳＨ－Ｐｘ（谷胱甘肽过氧化物酶）活性,血浆ＬＰＯ（过氧化脂质）进行测定。观察上述指标的随龄变化,甘草对老年大鼠体内上述指标的影响。结果表明,大鼠体内的抗氧化酶ＣＡＴ,ＧＳＨ－Ｐｘ活性在其成长阶段随年龄上升（Ｐ〈０．０１）,在衰老阶段随龄下降（Ｐ〈０．０１）。自由基代谢产物ＬＰＯ含量在血浆中随龄增加（Ｐ〈０．０１）甘草水     

褪黑素抗自由基作用及其机制

目的研究褪黑素（ＭＥＬ）的抗自由基作用,并探讨其作用机制。方法以丙二醛（ＭＤＡ）为指标,考察ＭＥＬ对四氯化碳（ＣＣｌ４）或氰化钾（ＫＣＮ）处理小鼠肝或脑组织脂质的保护作用;考察ＭＥＬ对环磷酰胺所致小鼠骨髓细胞微核的影响;观察ＭＥＬ清除羟自由基（·ＯＨ）作用,及对醋氨酚处理小鼠肝谷胱甘肽（ＧＳＨ）含量和大鼠红细胞超氧化物歧化酶（ＳＯＤ）、过氧化氢酶（ＣＡＴ）和全血谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）的影响。结果ＭＥＬ（２．０,１０．０ｍｇ·ｋｇ－１,ｉｐ）能显著对抗ＣＣｌ４或ＫＣＮ所致小鼠肝脏或脑组织丙二醛含量的增加。ＭＥＬ（１０．０ｍｇ·ｋｇ－１,ｉｐ）可明显抑制环磷酰胺引起的小鼠骨髓细胞微核增多。ＭＥＬ（０．０７８～５．０ｍｍｏｌ·Ｌ－１）可直接清除·ＯＨ。ＭＥＬ（１．０,１０．０ｍｇ·ｋｇ－１,ｉｐ）可显著对抗醋氨酚（ＡＡＰ）所致小鼠ＧＳＨ的耗竭作用。ＭＥＬ（１．０,５．０ｍｇ·ｋｇ－１,ｉｐ）亦可显著提高大鼠红细胞内ＳＯＤ、ＣＡＴ、全血ＧＳＨ－Ｐｘ活性。结论ＭＥＬ可保护脂质和核酸免受过氧化损伤,这可能与其直接清除·ＯＨ,提高机体ＧＳＨ含量及增强ＳＯＤ、ＣＡＴ、ＧＳＨ－Ｐｘ活力有关。     

31例突发聋患者血中LPO,SOD,GSH—Px变化

本实验测定３１例突发聋患者的过氧化脂质及超氧化物歧化酶，谷胱甘肽过氧化物酶含量，结果突发聋患者的ＬＰＯ明显高于对照组，ＳＯＤ，ＧＳＨ－Ｐｘ明显低于对照组，提示对细胞有损害作用的ＬＰＯ升高，自由基清除系统酶类ＳＯＤ、ＧＳＨ－Ｐｘ活性减低。     

苯染毒后小鼠血液，肝脏，脑的脂质过氧化水平

苯染毒后小鼠血液，肝脏，脑的脂质过氧化水平刘继文，宋旭红，黄贤仪，赵效国新疆医学院劳动卫生学教研室（乌鲁木齐８３００５４）我们对苯染毒小鼠的血液，肝脏和脑组织进行了超氧化物歧化酶（ＳＯＤ），谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）和过氧化脂质（ＬＰ）三项指...     

藻酸双酯钠和甘糖酯对急性心肌梗死患者红细胞变形能力保护作用…

为探讨藻酯双酯钠（ＰＳＳ）和甘糖酯（ＰＧＭＳ）对急性心肌梗死（ＡＭＩ）患者红细胞变形能力（ＥＤ）保护作用的机制，检测了５２例ＡＭＩ患者红细胞流动指数（ＥＦＩ），红细胞膜Ｎａ＾＋，Ｋ＾＋－ＡＴＰ酶和谷胱甘肽过氧化物酶ＧＳＨ－Ｐｘ活性及红细胞膜脂质过氧化物（ＬＰＯ）的变化，同时观察了ＰＳＳ和ＰＧＭＳ在体外对ＥＤ，Ｎａ＾＋，Ｋ＾＋－ＡＴＰ酶，ＧＳＨ－Ｐｘ和ＬＰＯ的影响，结果显示，ＡＭＩ患者ＥＦＩ，ＬＰＯ     

In vivo and in vitro effects of helenalin on mouse hepatic microsomal cytochrome P450

Helenalin, a natural plant product with significant antitumor activities, decreased male BDF1 mouse hepatic microsomal cytochrome P450 contents in vivo and in vitro. A single i.p. dose of 25 mg helenalin/kg body weight significantly (P less than 0.05) decreased microsomal cytochrome P450 contents and inhibited cytochrome P450-dependent mixed-function oxidase activities within 1-2 hr post-exposure. Helenalin (1.0 mM) decreased microsomal cytochrome P450 contents in vitro by 11% in the absence of NADPH and by 32% in the presence of NADPH. These in vitro and in vivo decreases in cytochrome P450 were accompanied by comparable decreases in total microsomal heme contents. Helenalin (1.0 mM) increased mouse hepatic microsomal oxygen consumption and NADPH utilization by 3.2 and 5.4 nmol/min/mg protein respectively. Helenalin (1.0 mM) significantly (P less than 0.05) increased microsomal lipid peroxidation in vitro, and this helenalin-induced increase in lipid peroxidation was inhibited completely by the addition of 0.05 mM EDTA. However, microsomal cytochrome P450 contents were equally affected by helenalin in the presence or absence of EDTA, suggesting that lipid peroxidation did not contribute to the helenalin-induced decrease in cytochrome P450. The addition of 0.05 mM hemin to microsomes treated in vitro with 1.0 mM helenalin resulted in a 58% recovery of cytochrome P450 contents. This ability of hemin to reconstitute cytochrome P450 in helenalin-treated microsomes suggests that helenalin produced a selective loss of heme from the cytochrome P450 holoprotein, and that the resulting cytochrome P450 apoprotein remained intact after helenalin treatment. The increased loss of microsomal cytochrome P450 produced by helenalin in the presence of NADPH suggests that a helenalin metabolite may be responsible for heme loss and the in vitro destruction of cytochrome P450.     

Acute Moderate Hypoxia in Conscious Rabbits: Effect on Hepatic Cytochrome P450 and on Reactive Oxygen Species

This study aimed to document whether acute moderate hypoxia modifies the amount and activity of hepatic cytochrome P450 and in addition, induces changes in the production or the ability to neutralize oxygen reactive species (ORS). Rabbits were exposed to a low partial pressure of oxygen (12%) for 8 or 24 h, killed, and the amount and activity of cytochrome P450, lipid peroxidation, microsomal chemiluminescence and enzymatic scavenger activity were assessed in the liver. After 8 h of hypoxia, total amount but not the activity of cytochrome P450 was decreased, although after 24 h of hypoxia, both the amount and the activity of cytochrome P450 were decreased. Hypoxia for 8 h increased the activity of glutathione peroxidase. However, after 24 h of hypoxia, lipid peroxidation, microsomal chemiluminescence and superoxide dismutase activity were increased, while hepatic glutathione and glutathione peroxidase activity were reduced, modifications that suggest an enhanced presence of ORS. In in-vitro studies, an ORS generating system reduced the activity of cytochrome P450 and enhanced lipid peroxidation of hepatic microsomal membranes, supporting the view that ORS can impair cytochrome P450. The results of the present study show that hypoxia induces changes in the amount and activity of cytochrome P450, as well as in the production or the ability to neutralize ORS, and that these changes are time-dependent.     

Cisplatin-induced changes in cytochrome P-450, lipid peroxidation and drug-metabolizing enzyme activities in rat kidney cortex

This study investigates the effects of 3 successive cisplatin administrations on rat kidney cytochrome P-450 and drug-metabolizing enzyme activities. Furthermore, because glutathione (GSH) and its related enzymatic system are involved in cellular detoxification processes, we examined the effects of cisplatin on lipid peroxidation, GSH levels, and GSH reductase and peroxidase activities. Cisplatin induced a decrease in cytochrome P-450, GSH, GSH S-transferase, GSH reductase and GSH peroxidase activities, and an increase in N-glucuronyl transferase, lipid peroxidation and oxidized glutathione (GSSG) in kidney cortical microsomes and cytosolic fractions. It is suggested that cisplatin nephrotoxicity could be explained by its affinity for SH-groups of several enzymes and SH-containing compounds. Among these, GSH and its related enzymatic system play a primary role. Moreover, cisplatin increases lipid peroxidation, which might participate in cisplatin nephrotoxicity.     

硒对氯化汞免疫毒性的影响及其机理

采用免疫毒理学和生化毒理学方法，研究了亚硒酸钠对氯化汞免疫毒性的影响及作用机理。结果表明：氯化汞染毒的ＩＣＲ小鼠血中碳廓清率、ＳＲＢＣ致敏小鼠的ＤＴＨ反应、ＤＮＣＢ所致的ＤＣＨ反应、血清溶血素形成和免疫器官脏体比均明显低于对照组，预先投以亚硒酸钠后，再给同剂量的氯化汞的小鼠上述各指标都有不同程度提高。免疫器官脂质过氧化作用，汞组与对照组比较：脂质过氧化物含量明显升高，而谷胱甘肽过氧化物酶活性明显降低；硒汞组与汞组比较：脂质过氧化物含量明显降低，而谷胱甘肽过氧化物酶活性明显升高。上述结果提示：亚硒酸钠对氯化汞所致的免疫毒性和免疫器官的脂质过氧化损伤具有保护作用     

阿魏酸钠对异烟肼和利福平肝损害小鼠的保护作用

目的：观察阿魏酸钠对异烟肼(INH)和利福平(RFP)肝毒性的保护作用。方法：分别测定血清谷丙转氨酶(ALT)的活性，肝匀浆中谷胱甘肽(GSH)及脂质过氧化物丙二醛(MDA)的含量，肝微粒体中细胞色素P450及其亚型2E1的活性。结果：阿魏酸钠可对抗INH和RFP合用引起的肝指数、血清ALT水平、肝匀浆中的MDA含量，以及细胞色素P450与亚型P450 2E1活性的升高，增加肝匀浆中GSH含量。病理学检查，阿魏酸钠明显减轻肝细胞的变性和坏死。结论：阿魏酸钠时INH和RFP肝毒性的保护作用与保护肝细胞膜、抑制脂质过氧化反应、清除自由基、降低RFP诱导的细胞色素P450酶系统有关。     

Glutathione peroxidase and glutathione transferase activity in rat lung and liver following cadmium inhalation

A 2-h inhalation exposure to 4.6 mg Cd/m3 decreased pulmonary total glutathione peroxidase (GSH Px) activity and non-selenium peroxidase (GSH non-Se-Px) activity but had no effect on GSH selenium peroxidase (Se-Px) activity. Seventy-two hours after exposure there was an increase in total GSH Px and GSH Se-Px activity and a decrease in GSH non-Se-Px activity. Exposure to 0.44 mg Cd/m3 for 2 h caused no effect on GSH Se-Px at either 0 or 72 h post exposure, but total GSH Px and GSH non-Se-Px activities were decreased up to 72 h post exposure. Exposure to 4.6 mg Cd/m3 caused an increase in hepatic GSH Se-Px activity 72 h post exposure, but no other significant changes were observed in the liver. Changes in GSH non-Se-Px activity did not relate to changes in GSH transferase (Tr) activity. The data suggest that alterations in GSH Px activity by Cd2+ may be due to changes in GSH non-Se-Px activity and that changes in pulmonary GSH Tr and GSH non-Se-Px activities may not be as closely linked as in the liver.     

Effects of perfluoro fatty acids on xenobiotic-metabolizing enzymes, enzymes which detoxify reactive forms of oxygen and lipid peroxidation in mouse liver.

Male mice were exposed via their diet to perfluoro fatty acids of various chain-lengths (2-10 carbon atoms) at different doses (0.02 and 0.1% weight) and for different periods of time (2-10 days). Thereafter, we monitored effects on liver and body weights and a number of hepatic parameters, including mitochondrial protein content, microsomal contents of cytochromes P450 and b5, NADPH-cytochrome P450 reductase activity [measured as NADPH-cytochrome c reductase (EC 1.6.2.3)], microsomal and cytosolic epoxide hydrolase (EC 3.3.2.3) activities, cytosolic DT-diaphorase (EC 1.6.99.2), glutathione transferase (EC 2.5.1.18), glutathione peroxidase (EC 1.11.1.9) and superoxide dismutase (EC 1.15.1.1) activities, and levels of thiobarbituric acid-reactive material (as an indicator of lipid peroxidation) in the mitochondrial subfraction. The most dramatic changes observed were a 5-9-fold increase in mitochondrial protein, a 3-6-fold increase in the microsomal content of cytochrome P450, a 3-10-fold increase in cytosolic DT-diaphorase activity, an approximately 2-fold increase in cytosolic epoxide hydrolase activity and as much as a 60% decrease in the level of thiobarbituric acid-reactive compounds in the mitochondrial fraction. Smaller increases in microsomal epoxide hydrolase activity and decreases in cytosolic glutathione peroxidase activity were also observed. Of the perfluoro fatty acids tested, perfluorooctanoic acid caused the largest changes in the parameters examined here. Dietary exposure of mice to a 0.02% dose of this substance for 10 days results in a maximal or near-maximal effect in most cases.     

Effect of dietary selenium on the metabolism of aflatoxin B1 in turkeys

To investigate the biochemical mechanism of the previously reported protective effect of dietary selenium against aflatoxin toxicity, the hepatic metabolism of aflatoxin B1 in turkey poults was examined at various dietary selenium concentrations. Diets were supplemented with 0.2, 2.0 or 4.0 ppm selenium (as sodium selenite) and 500 ng aflatoxin B1/g diet in an 18-day trial. Free and conjugated aflatoxin and metabolites were quantified using high-performance liquid chromatography. The proportion of liver aflatoxins in conjugated forms increased and the ratio of free aflatoxin B1/M1 decreased with increasing dietary selenium concentrations. These in vivo results provide evidence of selenium-induced enhancement of aflatoxin detoxification processes. In a similar experiment using 2.0 ppm selenium and 750 ng aflatoxin B1/g diet, the concentration of hepatic reduced glutathione, cytochrome P-450 and the activity of enzymes involved in the metabolism of aflatoxin B1 and glutathione were determined. Although the selenium supplement increased glutathione peroxidase activity, dietary selenium had no effect on reduced glutathione or cytochrome P-450 concentrations or on the activities of glutathione transferase E, glucuronyl transferase and cytochrome c reductase. These data indicate that the protective action of selenium is not mediated by an increase in glutathione availability for aflatoxin conjugation or by effects on the activities of these enzymes as measured in vitro.     

Prolonged phenobarbital pretreatment abolishes the early oxidative stress component induced in the liver by acute lindane intoxication

Lindane administration to rats (60 mg/kg b.w.) led to an enhancement in the oxidative stress status of the liver at 4 h after treatment, characterized by increases in hepatic thiobarbituric acid reactants (TBARS) formation and chemiluminescence, reduced glutathione (GSH) depletion, and diminution in the biliary content and release of GSH. These changes were observed in the absence of changes in either microsomal functions (cytochrome P450 content, NADPH-dependent superoxide radical production, and NADPH-cytochrome P450 reductase or NADPH oxidase activities) or in oxidative stress-related enzymatic activities (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase, and glutathione-S-transferases), over control values. Phenobarbital (PB) administration (0.1% in drinking water; 15 days) elicited an enhancement in liver microsomal functions, lipid peroxidation, and GSH content, without changes in oxidative stress-related enzymatic activities, except for the elevation in those of glutathione reductase and glutathione-S-transferase, compared to control rats. Lindane given to PB-pretreated rats did not alter liver microsomal functions, lipid peroxidation, glutathione status, or oxidative stress-related enzymatic activities, as compared to PB-pretreated animals. In addition, lindane induced periportal necrosis with hemorrhagic foci in untreated rats, but not in PB-pretreated animals. It is concluded that the early oxidative stress response of the liver to lindane and hepatic injury are suppressed by PB pretreatment via induction of microsomal enzymes in all zones of the hepatic acinus. reserved.     

Effect of phenobarbital and 3-methylcholanthrene on the early oxidative stress component induced by lindane in rat liver.

1. Lindane administered to untreated rats or rats pretreated with phenobarbital (PB) or 3-methylcholanthrene (MC) increased liver lipid peroxidation, of the same magnitude in all groups. 2. PB pretreatment produced a 50% increase in lipid peroxidation (TBAR) by liver homogenates and microsomes, an effect accompanied by increases in cytochrome P-450, NADPH-cytochrome P-450 reductase, NADPH oxidase and microsomal superoxide anion production, MC pretreatment resulted in increases in liver cytochrome P-450 and NADPH oxidase only. 3. Pretreatment of rats with PB, but not MC or lindane, gave increases in glutathione peroxidase and reductase. 4. Pretreatment with PB, but not MC, increased liver GSH. Lindane decreased liver GSH to the same extent as PB plus lindane. 5. Biliary GSH, GSSG and bile flow were decreased by lindane to similar extents in all groups. 6. Lindane induced periportal necrosis with haemorrhagic foci in all groups. 7. Data presented indicate that the early lipid peroxidative response of liver to lindane was unchanged by PB- or MC-stimulated hepatic microsomal enzyme induction.