大鼠自体原位肝移植模型中肠道羟自由基、丙二醛和总抗氧化能力的变化

目的: 建立SD大鼠自体原位肝移植模型,观察自体模拟肝移植后不同时期肠道黏膜病理学变化及肠组织的羟自由基(·OH)、丙二醛(MDA)和总抗氧化能力(T-AOC)的变化。方法: SD大鼠36只,随机分为假手术组(S组)和模型组(M组),模型组根据肝脏再灌注时间,再分为再灌注2 h模型组(M1组)、再灌注4 h模型组(M2组)、再灌注8 h模型组(M3组)、再灌注16 h模型组(M4组)和再灌注24 h模型组(M5组)5个亚组。对照组在麻醉后只进行开腹和血管的分离,不进行肝脏的阻断和灌注;模型组则进行自体肝移植手术。分别在肝脏再灌注后2、4、8、16、24 h取肠组织,观察其病理形态学变化及·OH、MDA和T-AOC的变化。结果: (1)与S组相比,M组大鼠肠黏膜在肝脏再灌注后出现明显的病理学损伤,可见上皮下间隙的扩大,甚至出现绒毛上皮和固有层分离,再灌注8 h时最为显著,再灌注24 h开始修复;(2)与S组相比,M2、M3和M4组·OH水平明显升高(P<0.05),M1、M2、M3组MDA含量明显升高(P<0.05),M1、M2、M3和M4组T-AOC明显降低(P<0.05)。结论: 自体原位肝移植可使大鼠肠黏膜·OH和MDA含量增加,T-AOC下降,肠道出现可逆性病理损伤。     

Xanthine oxidase activity and lipid peroxide content following different types of ischemia in the isolated rat heart

It is currently believed that reactive oxygen species are produced in the heart post-ischemia-reperfusion, causing pathophysiological disorders. Studies reported in the literature dealing with this subject have generated contradictory findings. The aim of this study was to assess the catalytic activity of the superoxide anion-producing enzyme xanthine oxidase, and the level of lipid peroxides in isolated rat heart muscle undergoing ischemia of varying duration and severity followed by reperfusion.Three levels of ischemia were investigated: total, and partial at either 0.10 or 0.35 ml/min (residual flow rate). Three different periods of ischemia were examined in each case. After each period of ischemia, followed by 10 min of reperfusion, the heart was frozen in liquid nitrogen. Xanthine oxidase activity and lipid peroxide levels were assayed in the cardiac homogenate and in the centrifuged supernatant, respectively. In the different experimental protocols studied here, both cardiac xanthine oxidase and lipid peroxide levels remained statistically unchanged compared to the continuously perfused control hearts. Moreover, in a recent study (Boucher et al., FEBS Lett. 203, 261–264, 1992), we were unable to detect reactive oxygen species in perfusate upon reperfusion of ischemic rat hearts.These results suggest that changes in xanthine oxidase activity during myocardial ischemia-reperfusion, and lipid peroxidation, as assessed by measuring thiobarbituric acid reactants and lipid hydroperoxides, are not predominant phenomena in ischemia-reperfusion-induced injury, at least in the experimental model used in this study. The significance of these results is discussed in the light of the popular point of view suggested first by McCord in 1985 concerning the conversion of xanthine dehydrogenase to xanthine oxidase in heart in the course of ischemia.     

Hydroxyl radical modification of polyguanylic acid: role of modified guanine in circulating SLE anti-DNA autoantibodies

The hydroxyl radical generated by UV irradiation of hydrogen peroxide cause an extensive damage to guanine residues of ribohomopolymer, polyguanylic acid, poly (G) as investigated by spectrophotometric measurements, agarose gel electrophoresis, Sephadex G-200 gel filtration and DEAE Sephadex A-25 column chromatography. Native and ROS-poly (G) were highly immunogenic inducing high titre antibodies in rabbits. The antibodies showed wide range of cross reactivity with various synthetic polynucleotides exhibiting B-, A-, and allied conformations. The diverse antigen binding characteristics of the induced antibodies resembles to those of naturally occurring lupus anti-DNA autoantibodies. Sera from various SLE patients showed preferential binding to ROS-poly (G) than native poly (G), indicating that oxidatively modified guanine residues are better recognised. The significance of these findings in the induction of SLE anti-DNA autoantibodies by oxygen free radicals modified guanine residues in DNA has been discussed.     

Edaravone,a free radical scavenger,retards the development of amygdala kindling in rats

This study evaluated the antiepileptogenic effects of edaravone, a newly developed radical scavenger, on the amygdala kindling rats. The afterdischarge duration (ADD), AD threshold (ADT), and seizure severity in animals were measured to study the anticonvulsant effects of edaravone (2 mg/kg or 20 mg/kg i.p. for 7 days) on fully kindled seizures. Furthermore, for the study of antiepileptogenesis effects of the drug (2 mg/kg or 20 mg/kg i.p. for 7 days), not only ADD and seizure severity during kindling but also both the pre- and post-kindling ADT were measured. Edaravone neither induces nor inhibits fully kindled seizures regardless of the dose; however high-dose edaravone (20 mg/kg) retarded kindling development together with shortened ADD and elevated ADT. The present data suggest that high-dose edaravone has an antiepileptogenic drug effect for the prevention of epilepsy. However, other chronic models and clinical trials are needed to confirm the effects of edaravone on the prevention of human epilepsy.     

磁处理酒对小鼠心组织自由基代谢的影响

目的:探讨磁处理酒对小鼠心组织中超氧化物歧化酶(SOD)、丙二醛(MDA)、一氧化氮(NO)和胆固醇含量的影响。方法:用邻苯三酚测定SOD,TBA法测定MDA,改良的Griess法测定NO,高铁-醋酸-硫酸显色法测定胆固醇。结果:与对照组相比,磁酒组SOD活力显著提高(P<0.05);白酒组MDA含量显著减少(P<0.05);磁酒组和白酒组SOD/MDA均显著提高(P<0.05);磁酒组MDA明显高于白酒组(P<0.01)。结论:磁处理白酒可影响小鼠心组织的自由基的代谢及胆固醇含量。     

Free radical oxidation and antioxidant activity in blood plasma and myocardium during long-term dipyridamole treatment

Activation of free radical oxidation and inhibition of antioxidant activity in mouse myocardium after long-term dipyridamole treatment were demonstrated using chemiluminescent techniques. At the same time, dipyridamole 10-fold inhibited free radical oxidation and slightly increased antioxidant activity in the plasma. Dipyridamole-induced platelet disaggregation was accompanied by an increase in platelet count.     

Skeletal muscle and heart antioxidant defences in response to sprint training

Although endurance training enhances the antioxidant defence of different tissues, information on the effect of sprint training is scanty. We examined the effect of sprint training on rat skeletal muscle and heart antioxidant defences. Male Wistar rats, 16–17 weeks old, were sprint trained on a treadmill for 6 weeks. Total glutathione levels and activities of glutathione peroxidase, glutathione reductase, glutathione S-transferase and superoxide dismutase in heart and various skeletal muscles were compared in trained and control sedentary animals. Lactate dehydrogenase and citrate synthase enzyme activities were measured in muscle to test the effects of training on glycolytic and oxidative metabolism. Sprint training significantly increased lactate dehydrogenase activity in predominantly fast glycolytic muscles and enhanced total glutathione contents of the superficial white quadriceps femoris, mixed gastrocnemius and fast-glycolytic extensor digitorum longus muscles. Oxidative metabolic capacity increased in plantaris muscle only. Compared with the control group, glutathione peroxidase activities in gastrocnemius, extensor digitorum longus muscles and heart also increased in sprint trained rats. Glutathione reductase activities increased significantly in the extensor digitorum longus muscle and heart. Glutathione S-transferase activity was also higher in the sprint trained extensor digitorum longus muscle. Sprint training did not influence glutathione levels or glutathione-related enzymes in the soleus muscle. Superoxide dismutase activity remained unchanged in skeletal muscle and heart. Sprint training selectively enhanced tissue antioxidant defences by increasing skeletal muscle glutathione content and upregulating glutathione redox cycle enzyme activities in fast and mixed fibre leg muscles and heart.     

Oxidases and oxygenases in regulation of vascular nitric oxide signaling and inflammatory responses

Nitric oxide (^aNO) is a freely diffusible inter-and in tracellular messenger produced by a variety of mammalian cells including vascular endothelium, neurons, smooth muscle cells, macrophages, neutrophils, platelets, and pulmonary epithelium. In smooth muscle cells, platelets, and neutrophils, ^aNO raises intracellular cyclic guanasine 5′-monophosphate levels by reacting with the actalytic heme domain of guanylate cylase, to activate it, thus leading to vasorelaxation, inhibition of platelet aggregation and inhibition of platelet and inflammatory cell adhesion to endothelium. The physiologic actions of ^aNO are highly dependent on changes in steady-state concentrations of reactive species and tissue-oxidant defense mechanisms. Vessel wall oxidases and oxygenases, in particular, are critical sources of oxygen radical production and can lead to an overall impairment of vascular ^aNO signaling, via the metalloprotein and free radical-mediated consumption of this vasoactive molecule. Vascular oxidase and oxygenase activities can thusaccount for the functional inactivation of ^aNO, leading to a prooxidative milieu and chronic inflammation.     

Roles of the tyrosine isomers meta-tyrosine and ortho-tyrosine in oxidative stress

The damage to cellular components by reactive oxygen species, termed oxidative stress, both increases with age and likely contributes to age-related diseases including Alzheimer’s disease, atherosclerosis, diabetes, and cataract formation. In the setting of oxidative stress, hydroxyl radicals can oxidize the benzyl ring of the amino acid phenylalanine, which then produces the abnormal tyrosine isomers meta-tyrosine or ortho-tyrosine. While elevations in m-tyrosine and o-tyrosine concentrations have been used as a biological marker of oxidative stress, there is emerging evidence from bacterial, plant, and mammalian studies demonstrating that these isomers, particularly m-tyrosine, directly produce adverse effects to cells and tissues. These new findings suggest that the abnormal tyrosine isomers could in fact represent mediators of the effects of oxidative stress. Consequently the accumulation of m- and o-tyrosine may disrupt cellular homeostasis and contribute to disease pathogenesis, and as result, effective defenses against oxidative stress can encompass not only the elimination of reactive oxygen species but also the metabolism and ultimately the removal of the abnormal tyrosine isomers from the cellular amino acid pool. Future research in this area is needed to clarify the biologic mechanisms by which the tyrosine isomers damage cells and disrupt the function of tissues and organs and to identify the metabolic pathways involved in removing the accumulated isomers after exposure to oxidative stress.     

动情期和动情间期小鼠输卵管中氧化应激和抗氧化基因表达差异

目的观察昆明(Kunming,KM)小鼠输卵管中氧化应激和抗氧化基因的表达是否随动情周期而改变。方法分别取动情期和动情间期小鼠输卵管进行RNA提取,用PCR芯片检测氧化应激和抗氧化基因表达的差别,然后用Real Time PCR对差异表达基因进一步验证。结果与动情间期比较,动情期小鼠输卵管中NADPH氧化酶1(NADPH oxidase1,NOX1)、谷胱甘肽过氧化物酶2(glutathion peroxidase 2,GPX2)、超氧化物歧化酶3(superoxide dismutase 3,SOD3)、一氧化氮合酶2(nitric oxide synthase 2,NOS2)等4个基因表达上调。结论动情期小鼠输卵管中NOX1、GPX2、SOD3和NOS2等4个基因表达上调,提示其可能参与维持动情期小鼠输卵管腔内适度的活性氧自由基(reactive oxygen species,ROS)和一氧化氮(nitric oxide,NO)水平,为卵子受精和早胚发育提供必要第二信号分子。     

在培养的心肌细胞中锌的抗氧自由基损伤作用的观察

本文通过向培养基中加入黄嘌呤和黄(?)呤氧化酶系统成分造成培养的心肌细胞受氧自由基伤害,以电生理的改变和BaCL_2引起心肌细胞停搏的闭浓度为指标,观察了微量元素Zn的抗氧化损伤作用。结果示:XOD组与对照组比较,动作电位APA、OS、MDP、TP、Vmax及APD_(50)各电参数明显减小。BaCl_2引起心肌细胞停搏的阈浓度亦减低。而加Zn组与对照组比较,以上结果除TP值偏低P<0.05外,其它参数则无显著性改变。加Zn组与XOD组相比,动作电位各电参数明显增大,BaCl_2引起心肌细胞停搏的阈浓度亦增高。提示Zn对培养的心肌细胞氧自由基所致的损伤具有保护作用。     

Spinal NADPH oxidase is a source of superoxide in the development of morphine-induced hyperalgesia and antinociceptive tolerance

The role of superoxide and its active byproduct peroxynitrite as mediators of nociceptive signaling is emerging. We have recently reported that nitration and inactivation of spinal mitochondrial superoxide dismutase (MnSOD) provides a critical source of these reactive oxygen and nitrogen species during central sensitization associated with the development of morphine-induced hyperalgesia and antinociceptive tolerance. In this study, we demonstrate that activation of spinal NADPH oxidase is another critical source for superoxide generation. Indeed, the development of morphine-induced hyperalgesia and antinociceptive tolerance was associated with increased activation of NADPH oxidase and superoxide release. Co-administration of morphine with systemic delivery of two structurally unrelated NADPH oxidase inhibitors namely apocynin or diphenyleneiodonium (DPI), blocked NADPH oxidase activation and the development of hyperalgesia and antinociceptive tolerance at doses devoid of behavioral side effects. These results suggest that activation of spinal NADPH oxidase contributes to the development of morphine-induced hyperalgesia and antinociceptive tolerance. The role of spinal NADPH oxidase was confirmed by showing that intrathecal delivery of apocynin blocked these events. Our results are the first to implicate the contribution of NADPH oxidase as an enzymatic source of superoxide and thus peroxynitrite in the development of central sensitization associated with morphine-induced hyperalgesia and antinociceptive tolerance. These results continue to support the critical role of these reactive oxygen and nitrogen species in pain while advancing our knowledge of their biomolecular sources.     

A neuroanatomical analysis of the effects of a memory impairing dose of scopolamine in the rat brain using cytochrome c oxidase as principle marker

Acetylcholine plays a role in mnemonic and attentional processes, but also in locomotor and anxiety-related behavior. Receptor blockage by scopolamine can therefore induce cognitive as well as motor deficits and increase anxiety levels. Here we show that scopolamine, at a dose that has previously been found to affect learning and memory performance (0.1 mg/kg i.p.), has a widespread effect on cytochrome c oxidase histochemistry in various regions of the rat brain. We found a down-regulation of cytochrome c oxidase in the nucleus basalis, in movement-related structures such as the primary motor cortex and the globus pallidus, memory-related structures such as the CA1 subfield of the hippocampus and perirhinal cortex and in anxiety-related structures like the amygdala, which also plays a role in memory. However choline acetyltransferase levels were only affected in the CA1 subfield of the hippocampus and both, choline acetyltransferase and c-Fos expression levels were decreased in the amygdala. These findings corroborate strong cognitive behavioral effects of this drug, but also suggest possible anxiety- and locomotor-related changes in subjects. Moreover, they present histochemical evidence that the effects of scopolamine are not ultimately restricted to cognitive parameters.     

Induction of HSPs and antioxidant defense enzymes during activation of free radical oxidation at the early stage of hypokinesia

We studied the stress component of the early stage of hypokinesia during hindlimb unloading. The intensity of free radical processes was evaluated and the content of protective proteins (antioxidant defense enzymes and proteins of the HSP family) was measured in the heart and liver. Three-hour hypokinesia increased the content of constitutive protective proteins, including hemoxygenase-2 and antioxidant defense enzymes, in the heart. Hypokinesia for 72 h was accompanied by more potent activation of antioxidant defense enzymes and increase in the content of inducible hemoxygenase-1, which leads to partial compensation of activated free radical oxidation. In the liver, hypokinesia of different duration suppressed the protective systems: the synthesis of inducible and constitutive hemoxygenases and antioxidant defense enzymes decreased, while the sensitivity of liver membrane structures to reactive oxygen species increased. We revealed a tissue-specific response to hypokinesia: pronounced damaging effect predominated in the liver and partial compensation of elevated production of reactive oxygen species was observed in the heart due to activation of protective systems. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 143, No. 4, pp. 378–382, April, 2007     

The evaluation of effects of lipoic acid on the lipid peroxidation,nitrite formation and antioxidant enzymes in the hippocampus of rats after pilocarpine-induced seizures

It has been suggested that pilocarpine-induced seizures is mediated by increases in oxidative stress. Current researches have suggested that antioxidant compounds may afford some level of neuroprotection against the neurotoxicity of seizures in cellular level. The objective of the present study was to evaluate the neuroprotective effects of lipoic acid (LA) in rats, against the observed oxidative stress during seizures induced by pilocarpine. Wistar rats were treated with 0.9% saline (i.p., control group), LA (10 mg/kg, i.p., LA group), pilocarpine (400 mg/kg, i.p., pilocarpine group), and the association of LA (10 mg/kg, i.p.) plus pilocarpine (400 mg/kg, i.p.), 30 min before of administration of LA (LA plus pilocarpine group). After the treatments all groups were observed for 6 h. The enzyme activities as well as the lipid peroxidation and nitrite concentrations were measured using spectrophotometric methods and the results compared to values obtained from saline and pilocarpine-treated animals. Protective effects of LA were also evaluated on the same parameters. In pilocarpine group there was a significant increase in lipid peroxidation and nitrite level. However, no alteration was observed in superoxide dismutase and catalase activities. Antioxidant treatment significantly reduced the lipid peroxidation level and nitrite content as well as increased the superoxide dismutase and catalase activities in hippocampus of rats after seizures induced by pilocarpine. Our findings strongly support the hypothesis that oxidative stress in hippocampus occurs during seizures induced by pilocarpine, proving that brain damage induced by the oxidative process plays a crucial role in seizures pathogenic consequences, and also imply that strong protective effect could be achieved using lipoic acid as an antioxidant.     

Intensification of free radical oxidation of low-density lipoproteins in the plasma of patients with ischemic heart disease receiving beta-hydroxy-beta-methylglutaryl-coenzyme A reductase inhibitor cerivastatin and inhibition of low-density lipoprotein peroxidation with antioxidant probucol

Inhibitors of the key enzyme of cholesterol biosynthesis beta-hydroxy-beta-methylglutaryl-coenzyme A reductase (statins) decrease cholesterol content in atherogenic low-density lipoproteins in patients with coronary heart disease and hypercholesterolemia, but inhibited biosynthesis of ubiquinone Q10 protecting low-density lipoproteins from free radical oxidation. Cerivastatin in a daily dose of 0.4 mg markedly increased the content of lipid peroxides in low-density lipoproteins. However, complex therapy with cerivastatin and antioxidant probucol (250 mg/day) was accompanied by a sharp decrease in the content of lipid peroxides in low-density lipoproteins in patients with coronary heart disease in vivo. These data indicate that antioxidant agents should be used in combination with inhibitors of beta-hydroxy-beta-methylglutaryl-coenzyme A reductase (hypolipidemic preparations) for the therapy of patients with coronary heart disease.     

Neutrophil free oxygen radical production and blood total antioxidant capacity in patients with coronary heart disease using various medications

Despite convincing results of studies in vitro, less is known about the effects of antioxidants on in vivo redox balance in humans. We developed a novel parameter of in vivo redox balance, and studied it and its relation to dental infections in 51 patients on medication for coronary heart disease (CHD) and 39 random controls matched for age group, sex, social class and locality. In vivo redox balance was the ratio of plasma antioxidant capacity, as measured with radical-trapping assay, to neutrophil respiratory burst capacity, as measured with whole blood chemiluminescence assay. Dental infections were quantitated with four rating scales. CHD patients had higher values than controls. Patients on acetosalicylic acid (ASA), diuretics or beta blockers, but not the ones on calcium channel blocker, had significantly higher redox balance than non-users. Combination of calcium channel blockers and ASA was associated with redox balance similar to taking beta blockers or diuretics. Diuretics and ASA were independent determinants of redox balance in multivariate analyses. Redox balance did not correlate with severity of dental infections (Spearman's r 0.06 to 0.11). The results contrast experimental data indicating that calcium channel blockers are as antioxidants superior to other cardiovascular drugs. Total antioxidant capacity in parallel with oxygen species production capacity should be considered in attempts to solve the antioxidant paradox.     

钙离子浓度变化对大鼠缺血心室致颤阈值的影响及其与cAMP、cGMP及ATP的关系

本文目的是观察不同钙离子浓度([Ca~(2 )])对急性局部缺血大鼠心脏室颤阈(VFT)的影响及其与心肌cAMP、cGMP和ATP含量变化的关系。结果表明,[Ca~(2 )]与缺血心脏VFT下降幅度呈正相关(r=0.7998,p<0.05);而[Ca~(2 )]与缺血心肌cAMP/cGMP比值、ATP含量则呈负相关(分别r=-0.887、r=-0.864,均p<0.05);缺血心脏VFT下降幅度与cAMP/cGMP比值亦呈显著负相关(r=-0.992,p<0.01),提示心肌细胞内游离Ca~(2 )水平可能是缺血心室易颤性(VV)的决定因素;cAMP水平或cAMP/cGMP比值则可能是通过影响Ca~(2 )内流而起作用的间接因素;而ATP贮量对缺血心脏VFT下降可能有一定保护作用。     

乳腺癌改良根治术后调强放疗与常规放疗疗效及对心肺的影响

目的:探讨乳腺癌改良根治术后调强放疗与常规放疗的疗效及对心肺的影响。方法:选择乳腺癌改良根治术患者60例,按照不同放疗方法分为观察组30例与对照组30例。观察组患者行调强放疗,对照组患者行常规放疗。比较两组近期,放疗前后心肌酶肌钙蛋白和肺功能变化,以及患肺和心脏受照剂量变化。结果:两组近期总有效率比较无显著差异(P>0.05)。两组放疗后肌钙蛋白水平较放疗前升高(P<0.05);观察组放疗后肌钙蛋白水平低于对照组(P<0.05)。两组放疗后射血分数较放疗前降低,而LADs和LVDd较治疗前升高(P<0.05);观察组放疗后射血分数高于对照组,而LADs和LVDd低于对照组(P<0.05)。两组患侧肺脏指数V95比较无显著差异(P>0.05);观察组患侧肺脏指数V105和V110低于对照组(P<0.05)。观察组心脏指数V30、V40和V50低于对照组(P<0.05)。结论:乳腺癌改良根治术后调强放疗与常规放疗疗效相当,而调强放疗对心脏和肺脏影响小,可减轻心脏和肺脏的放射性损伤。     

Effects of N-acetylcysteine on nicotinamide dinucleotide phosphate oxidase activation and antioxidant status in heart, lung, liver and kidney in streptozotocin-induced diabetic rats

Purpose

Hyperglycemia increases reactive oxygen species (ROS) and the resulting oxidative stress plays a key role in the pathogenesis of diabetic complications. Nicotinamide dinucleotide phosphate (NADPH) oxidase is one of the major sources of ROS production in diabetes. We, therefore, examined the possibility that NADPH oxidase activation is increased in various tissues, and that the antioxidant N-acetylcysteine (NAC) may have tissue specific effects on NADPH oxidase and tissue antioxidant status in diabetes.

Materials and Methods

Control (C) and streptozotocin-induced diabetic (D) rats were treated either with NAC (1.5 g/kg/day) orally or placebo for 4 weeks. The plasma, heart, lung, liver, kidney were harvested immediately and stored for biochemical or immunoblot analysis.

Results

levels of free 15-F_2t-isoprostane were increased in plasma, heart, lung, liver and kidney tissues in diabetic rats, accompanied with significantly increased membrane translocation of the NADPH oxidase subunit p67phox in all tissues and increased expression of the membrane-bound subunit p22phox in heart, lung and kidney. The tissue antioxidant activity in lung, liver and kidney was decreased in diabetic rats, while it was increased in heart tissue. NAC reduced the expression of p22phox and p67phox, suppressed p67phox membrane translocation, and reduced free 15-F_2t-isoprostane levels in all tissues. NAC increased antioxidant activity in liver and lung, but did not significantly affect antioxidant activity in heart and kidney.

Conclusion

The current study shows that NAC inhibits NADPH oxidase activation in diabetes and attenuates tissue oxidative damage in all organs, even though its effects on antioxidant activity are tissue specific.