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1.
In a previous study oxidative damage markers - lipid peroxidation and protein oxidation - were determined in organs of wild Caiman yacare captured in winter-2001 and summer-2002 at various developmental stages. An increase in oxidative damage occurred in the hatchling-juvenile transition (but not in the juvenile-adult transition) and winter-summer transition (in juveniles), suggesting that oxidative stress is associated with development and season. Herein the effect of development and season on glutathione (GSH) metabolism and the effect of development on the activity of antioxidant enzymes (catalase, glutathione peroxidase, glutathione reductase and glutathione S-transferase) and glucose 6-phosphate dehydrogenase were analyzed. The ratio GSSG:GSH-eq increased in lung, liver, kidney and brain by 1.8- to 4-fold in the embryo/hatchling to juvenile transition. No changes occurred in juvenile-adult transition. GSSG:GSH-eq across seasons was significantly elevated in summer. Total-glutathione content was mostly stable in various organs; in liver it increased in the embryo-juvenile transition. Enzyme activities were only determined in summer-animals (embryos, hatchlings and juveniles). For most antioxidant enzymes, activities increased from embryo/hatchling to juvenile in liver and Kidney. In lung, there was an inverse trend for enzyme activities and total glutathione content. Thus, increased metabolic rates during early caiman growth - in embryo-juvenile transition - appears to be related to redox imbalance as suggested by increased GSSG:GSH-eq and activation of antioxidant defenses. Differences in oxidative stress across seasons were related with summer-winter nocturnal temperatures. These results, as a whole, were interpreted in the context of ecological biochemistry.  相似文献   

2.
Antioxidant defenses within the lung are pivotal in preventing damage from oxidative toxicants. There have also been several reports with conflicting results on the antioxidant system during aging. In this study, we attempted to investigate age-related alterations in both antioxidant enzyme activities and thiobarbituric acid-reactive substances (TBARS), a product of lipid peroxidation, in the whole lung of control and sulfur dioxide (SO2) exposed rats of different age groups (3-, 12-, and 24-months-old). Swiss-Albino Male rats were exposed to 10 ppm SO2 1 hr/day, 7 days/week for 6 weeks. The antioxidant enzymes examined include Cu,Zn-superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione S-transferase (GST). A mixed pattern of age-associated alterations in antioxidant activities was observed. SOD, GSH-Px and GST activities were increased with age, but CAT activity was decreased. Lung SOD, GSH-Px and GST activities were also increased in response to SO2. The level of TBARS was increased with age. SO2 exposure stimulated lipid peroxide formation in the lung as indicated by an increase in the level of TBARS. These findings suggest that both aging and SO2 exposure may impose an oxidative stress to the body. We conclude that the increase in the activities of the antioxidant enzymes of the lung during aging, could be interpreted as a positive feedback mechanism in response to rising lipid peroxidation.  相似文献   

3.
Antioxidant enzyme activities, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and total glutathione concentration were determined in guinea pig lung and liver over the final period of gestation (days 50-68) and at several ages post-partum. Pulmonary antioxidant capacity increased markedly over the final days of gestation, individual changes ranging from 29% (glutathione) to 198% (GSH-Px). Liver antioxidant capacity was always 4-fold to 10-fold greater than that of the lung and exhibited very similar developmental profiles to those observed in the lung. From day 60 gestation to term (68 days), activity of the liver antioxidants increased, ranging from 246% (CAT) to 610% (glutathione). A number of antioxidants in both lung and liver exhibited either immediate pre- or post-birth decreases in activity. These falls could not be attributed to the way in which the results were expressed: i.e. they were similar, expressed per unit DNA, per unit protein, or per g wet wt. Following birth, liver antioxidant capacity increased such that the highest enzyme activities or glutathione concentration were recorded at 66 days post-partum. In lung, only Mn-SOD and glutathione exhibited higher levels at 66 days postpartum than at birth. In combination, these results of pulmonary and hepatic antioxidant enzyme activity indicate that the lung is not unique in acquiring increased antioxidant protection in the final period of gestation. They also suggest that a tissue's antioxidant requirement is dictated more by metabolic rate (hence free radical production) than incident partial pressure of oxygen.  相似文献   

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6.
Barbel (Barbus barbus) is the final host of the adult worm Pomphorhynchus laevis (Acanthocephala), one of the most abundant and widespread intestinal parasites of European freshwater fish. During the course of the present study, we analyzed the activities of the glutathione-dependent enzymes glutathione peroxidase (GSH-Px), glutathione reductase (GR) and the phase II biotransformation enzyme glutathione-S-transferase (GST) as well as the concentrations of total glutathione (GSH), sulfhydryl (SH) groups and vitamin E (Vit E) in the liver and intestine of B. barbus and in its intestinal parasite P. laevis. The fish were caught from the Danube River (Serbia) in spring and summer. We detected that GSH-Px activity in fish liver was higher in spring. GR activity was significantly higher in spring in all investigated samples, while GST activity was significantly higher in spring in fish liver and in the parasite. At that time, GST activity was ten times higher in the parasite than in fish tissues. The concentration of GSH was increased in barbel liver in spring. In summer, the concentration of SH groups was significantly increased, while the concentration of Vit E was significantly decreased in fish tissues and in the parasite. We performed Canonical Discriminant Analysis, which revealed differentiation among the examined tissues during both seasons based on the all measured antioxidant components. We found that the seasonal patterns of antioxidant defense in the parasite are closely correlated with seasonal variation and physiological change in the host and represent the parasite's adaptation to changes in the host's antioxidant system. The present investigation contributes to general knowledge and provides a basis for future studies of glutathione-dependent enzymes and non-enzymatic low molecular mass antioxidants as potential biomarkers for monitoring the influence of the environment on fishes and their parasites.  相似文献   

7.
研究了浓度为0、1、5、10、15、20 mg/L的新兴离子液体溴化1-己基-3-甲基咪唑([C6mim]Br)在24h、48h、72h和96h对斜生栅藻还原型谷胱甘肽(GSH)及其代谢酶-谷胱甘肽过氧化物酶(GPX)、谷胱甘肽转硫酶(GST)和谷胱甘肽还原酶(GR)的影响。结果表明:GSH含量在24h、48h和72h时,在最低处理浓度下不变,其他处理浓度下随胁迫浓度增加而降低,96h时则与对照无差异或较小;GPX和GST的活性在72h之前明显升高(最高浓度组的GST活性有波动),96h时均降低至对照水平;GR活性在24h时,[C6mim]Br=1 mg/L时升高,之后降低,在48h增高至对照水平,72h时,[C6mim]Br≥10 mg/L的处理组高于对照水平,96h时,除最低处理组外,均降至对照水平以下。GR是GSH系统中的限速酶,GST则是该系统中活性和灵敏性最高的酶,可作为[C6mim]Br胁迫时的敏感的生物标志物。1 mg/L的[C6mim]Br可引起藻细胞的氧化胁迫,具有环境毒性。  相似文献   

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9.
The objective of this study was to compare the effect of cholesterol feeding of rats and rabbits. The levels of lipid peroxidation products and oxysterols in the plasma of the two species plus the antioxidant enzyme activities in the liver and erythrocytes were measured to explain their different susceptibilities to atherosclerosis. Our study showed that rats are less susceptible than are rabbits to the atherogenic effect of a cholesterol-rich diet because of differences in lipid peroxidation products as well as antioxidant enzymes activities in their livers. In rabbits, cholesterol feeding produced severe hypercholesterolemia (43-fold increase) and increased plasma and liver lipid peroxidation. Total as well as the individual oxysterol contents of 7alpha-, 7beta-hydroxycholesterol, alpha-epoxy, beta-epoxycholesterol, cholestanetriol, 7-keto, and 27-hydroxycholesterol significantly increased in the plasma of hypercholesterolemic (HC) rabbits. Erythrocyte glutathione peroxidase (GSH-Px) activity significantly decreased whereas catalase activity significantly increased in HC rabbits. In rats cholesterol feeding increased the plasma cholesterol only twofold and had no effect on plasma or liver lipid peroxidation. Only 7alpha- and 7beta-hydroxycholesterol increased and no change was observed in any of the antioxidant enzymes activity in the erythrocytes. Although cholesterol feeding caused a 10-fold increase of liver cholesterol as ester in both rats and rabbits, the antioxidant enzyme GSH-Px and catalase activities in the liver significantly increased in rats but significantly decreased in rabbits. The increase of GSH-Px and catalase activities in the liver of cholesterol fed rats could have a protective role against oxidation, thus preventing the formation of lipid peroxidation and oxysterols.  相似文献   

10.
The activities of hepatic cytosolic glutathione S-transferases (GSTs) towards 1,2-dichloro-4-nitrobenzene in male rats were higher than those in females, however, the enzyme activities towards 1-chloro-2,4-dinitrobenzene were not significantly different between the two sexes. SDS-PAGE analysis of GSTs purified from male and female rat hepatic cytosols by affinity column chromatography showed that there was a significant difference in the subunit composition between the two sexes. With regard to the several isozymes of GSTs in male and female rats, isozymes with basic and neutral/acidic isoelectric points were separated into seven molecular species by chromatofocusing. These sex differences in the quantitative proportions of GST isozymes were also confirmed by immunotitration using anti-GST-BL and -AC antibodies. On the other hand, glutathione peroxidase (GSH-Px) activities in rat hepatic cytosol towards hydrogen peroxide and cumene hydroperoxide were markedly higher in females than in males. Of the two types of GSH-Px, selenoenzyme (Se-GSH-Px) and the Se-independent enzyme (non-Se-GSH-Px), the former was found to be mainly responsible for the sex difference in the enzyme activities. Moreover, the GSH-Px activity of GSTs, non-Se-GSH-Px, was also higher in females than that in males. Since GST isozymes of the BL type are known to possess GSH-Px activity towards cumene hydroperoxide, the increased activities of non-Se-GSH-Px in the female hepatic cytosol seemed to be mainly due to the increased transferase activities of the isozymes, GST-L2 and -BL.  相似文献   

11.
【目的】研究蚯蚓提取物对家蚕Bombyx mori中肠组织氧化应激及抗氧化酶含量的影响,探究蚯蚓提取物的抗氧化功能。【方法】分别给家蚕5龄幼虫饲喂蚯蚓(赤子爱胜蚓Eisenia foetida)提取液原液的50, 100和200倍稀释液处理后的桑叶,测定处理6 d后家蚕中肠组织中氧化损伤产物丙二醛(MDA)和乳酸脱氢酶(LDH)的含量;利用qRT-PCR检测家蚕中肠组织中抗氧化酶关键基因(Cat,Sod和GSH-Px)的mRNA表达水平;同时采用ELISA法检测中肠组织中抗氧化酶[过氧化氢酶(CAT)、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)]含量及总抗氧化能力(T-AOC)。【结果】与对照组相比,50, 100和200倍稀释组家蚕中肠组织中MDA, CAT, SOD和GSH-Px含量及T-AOC均差异不显著,200倍稀释组LDH含量显著降低了9.85%,100倍稀释组中肠中Cat和GSH-Px的表达量均显著高于对照组,3个稀释组中Sod的表达量均显著高于对照组。【结论】添食蚯蚓提取物可通过降低家蚕中肠LDH含量、提高抗氧化酶基因的表达水平进而提高家蚕的抗氧化能力。  相似文献   

12.
Saadet Gü          reyya B   lmen  Dijle K   pmen Korgun  Piraye Yargi  o  lu  Aysel A  ar 《Free radical research》2001,34(6):621-627
Antioxidant defenses within the lung are pivotal in preventing damage from oxidative toxicants. There have also been several reports with conflicting results on the antioxidant system during aging. In this study, we attempted to investigate age-related alterations in both antioxidant enzyme activities and thiobarbituric acid-reactive substances (TBARS), a product of lipid peroxidation, in the whole lung of control and sulfur dioxide (SO2) exposed rats of different age groups (3-, 12-, and 24-months-old). Swiss-Albino Male rats were exposed to 10 ppm SO2 1 hr/day, 7 days/week for 6 weeks. The antioxidant enzymes examined include Cu,Zn-superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione S-transferase (GST). A mixed pattern of age-associated alterations in antioxidant activities was observed. SOD, GSH-Px and GST activities were increased with age, but CAT activity was decreased. Lung SOD, GSH-Px and GST activities were also increased in response to SO2. The level of TBARS was increased with age. SO2 exposure stimulated lipid peroxide formation in the lung as indicated by an increase in the level of TBARS. These findings suggest that both aging and SO2 exposure may impose an oxidative stress to the body. We conclude that the increase in the activities of the antioxidant enzymes of the lung during aging, could be interpreted as a positive feedback mechanism in response to rising lipid peroxidation.  相似文献   

13.
Obesity-related cardiac lipid accumulation is associated with increased myocardial oxidative stress. The role of the antioxidant glutathione in cardiac lipotoxicity is unclear. Cystathionine β-synthase (Cbs) catalyzes the first step in the trans-sulfuration of homocysteine to cysteine, which is estimated to provide ~50% of cysteine for hepatic glutathione biosynthesis. As cardiac glutathione is a reflection of the liver glutathione pool, we hypothesize that mice heterozygous for targeted disruption of Cbs (Cbs(+/-)) are more susceptible to obesity-related cardiolipotoxicity because of impaired liver glutathione synthesis. Cbs(+/+) and Cbs(+/-) mice were fed a high fat diet (60% energy) from weaning for 13 weeks to induce obesity and had similar increases in body weight and body fat. This was accompanied by increased hepatic triglyceride but no differences in hepatic glutathione levels compared with mice fed chow. However, Cbs(+/-) mice with diet-induced obesity had greater glucose intolerance and lower total and reduced glutathione levels in the heart, accompanied by lower plasma cysteine levels compared with Cbs(+/+) mice. Higher triglyceride concentrations, increased oxidative stress, and increased markers of apoptosis were also observed in heart from Cbs(+/-) mice with diet-induced obesity compared with Cbs(+/+) mice. This study suggests a novel role for Cbs in maintaining the cardiac glutathione pool and protecting against cardiac lipid accumulation and oxidative stress during diet-induced obesity in mice.  相似文献   

14.
Glutathione plays a central role in the maintenance of cellular antioxidant defense. The alterations in the glutathione and associated recyclic enzymes caused by both exercise training and ethanol are well documented; however, their interactive effects with age are not well understood. Therefore, the influence of ageing and the interactive effects of exercise training and ethanol on the myocardial glutathione system in 3 months and 18 months old rats were examined. The results showed a significant (p<0.01) reduction in GSH content, Se and non-Se GSH-Px, GR and GST activities in the myocardium of rat with age. A significant increase (p<0.05) in the activities of these enzymes was observed in both age groups of rats in response to exercise training. This exercise-induced elevation of Se and non-Se GSH-Px and GR activities was more pronounced in the 18 months old rats when compared to 3 months old rats. Ethanol consumption significantly (p<0.05) reduced the GSH content, Se and non-Se GSH-Px and GR activities in both age groups of rats. In contrast, ethanol consumption significantly (p<0.05) increased the activity of GST. The combined action of exercise plus ethanol significantly (p<0.05) elevated the GSH content, Se and non-Se GSH-Px, GR and GST activities when compared to the ethanol treated rats in both age groups, indicating the suppression of ethanol-induced oxidative stress by exercise training. In conclusion, there was a compensatory myocardial response lessening ethanol-induced oxidative stress by exercise training, which seemed to result from the higher activity of glutathione recycling and utilizing enzymes, which may be critical for preventing chronic oxidative damage to the myocardium during ageing and even due to ethanol consumption.  相似文献   

15.
The activities of glutathione dependent antioxidant enzymes were measured in subcellular fractions of whole brain homogenates prepared from ovariectomized (OVX) female rats, untreated or treated 2 h or 24 h prior to sacrifice with a single dose of 2 mg progesterone (P) or 5 micrograms estradiol benzoate (EB). Glutathione peroxidase (GSH-Px) activity was not changed following systemic administration of EB, but P increased GSH-Px in the brain of OVX rats 24 h after the treatment. The activity of glutathione reductase (GR) was suppressed by EB short time, only 2 h following treatment, whereas P increased the enzyme activity 24 h after treatment. On the other hand, the activities of catalase (CAT) and glutathione-S-transferase (GST) were not changed following systemic administration of EB or P. The present work was carried out to study the involvement of ovarian steroids, especially P, in the control of GSH-Px and GR activities, and our results suggest that oxidative stress in the brain of female rats may be modulated by the level of progesterone.  相似文献   

16.
Zaharieva TB  Abadía J 《Protoplasma》2003,221(3-4):269-275
Summary.  The effects of Fe deficiency stress on the levels of ascorbate and glutathione, and on the activities of the enzymes ferric chelate reductase, glutathione reductase (EC 1.6.4.2), ascorbate free-radical reductase (EC 1.6.5.4) and ascorbate peroxidase (EC 1.11.1.11), have been investigated in sugar beet (Beta vulgaris L.) roots. Plasma membrane vesicles and cytosolic fractions were isolated from the roots of the plants grown in nutrient solutions in the absence or presence of Fe for two weeks. Plants responded to Fe deficiency not only with a 20-fold increase in root ferric chelate reductase activity, but also with moderately increased levels of the general reductants ascorbate (2-fold) and glutathione (1.6-fold). The enzymes of the ascorbate-glutathione cycle in roots were also affected by Fe deficiency. Glutathione reductase activity was enhanced 1.4-fold with Fe deficiency, associated to an increased ratio of reduced to oxidized glutathione, from 3.1 to 5.2. The plasma membrane fraction from iron-deficient roots showed 1.7-fold higher ascorbate free-radical reductase activity, whereas in the cytosolic fraction the enzyme activity was not affected by Fe deficiency. The activity of the cytosolic hemoprotein ascorbate peroxidase decreased approximately by 50% with Fe deprivation. These results show that sugar beet responds to Fe deficiency with metabolic changes affecting components of the ascorbate-glutathione cycle in root cells. This suggests that the ascorbate-glutathione cycle would play certain roles in the general Fe deficiency stress responses in strategy I plants. Received November 19, 2001; accepted September 30, 2002; published online April 2, 2003 RID="*" ID="*" Correspondence and reprints: Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, CSIC, Apartado 202, 50080 Zaragoza, Spain.  相似文献   

17.
Glutathione has been implicated to function in cytoprotection against cadmium toxicity. The mechanism by which glutathione plays this role has not been well understood. Because glutathione is an important antioxidant and several studies have shown that cadmium induces oxidative stress, this study was undertaken to determine whether development of cadmium resistance is linked to enhanced antioxidant activities. A cadmium-resistant subpopulation of human lung carcinoma A549 cells, which was developed by repeatedly exposing the cells to step-wise increased cadmium concentrations, was compared to a cadmium-sensitive one. The acquired cadmium resistance resulted from neither decreased cadmium uptake nor enhanced cellular metallothionein synthesis. Glutathione content, however, was markedly elevated in the cadmium-resistant cells. In contrast, the activities of the glutathione redox cycle related enzymes, glutathione peroxidase and reductase, were unchanged. Two other antioxidant enzymes, superoxide dismutase and catalase, were also not altered. The results suggest that the development of cadmium resistance in A549 cells unlikely results from enhanced antioxidant enzyme activities, although it is associated with elevated cellular glutathione levels. In addition, measurement of the mRNA and DNA levels for γ-glutamyleysteine synthetase, the rate-limiting enzyme for glutathione biosynthesis, revealed that enhanced expression of the enzyme but not gene amplification is likely responsible for the elevation of cellular glutathione levels.  相似文献   

18.
Depletion of glutathione in the substantia nigra is one of the earliest changes observed in Parkinson's disease (PD) and could initiate dopaminergic neuronal degeneration. Nevertheless, experimental glutathione depletion does not result in preferential toxicity to dopaminergic neurons either in vivo or in vitro. Moreover, dopaminergic neurons in culture are preferentially resistant to the toxicity of glutathione depletion, possibly owing to differences in cellular glutathione peroxidase (GPx1) function. However, mesencephalic cultures from GPx1-knockout and wild-type mice were equally susceptible to the toxicity of glutathione depletion, indicating that glutathione also has GPx1-independent functions in neuronal survival. In addition, dopaminergic neurons were more resistant to the toxicity of both glutathione depletion and treatment with peroxides than nondopaminergic neurons regardless of their GPx1 status. To explain this enhanced antioxidant capacity, we hypothesized that tetrahydrobiopterin (BH(4)) may function as an antioxidant in dopaminergic neurons. In agreement, inhibition of BH(4) synthesis increased the susceptibility of dopaminergic neurons to the toxicity of glutathione depletion, whereas increasing BH(4) levels completely protected nondopaminergic neurons against it. Our results suggest that BH(4) functions as a complementary antioxidant to the glutathione/glutathione peroxidase system and that changes in BH(4) levels may contribute to the pathogenesis of PD.  相似文献   

19.
Removal of reproductive ‘sink’ i.e. spikelets from wheat at anthesis delays the rate of flag leaf senescence. In this work, the antioxidant defense was studied in the flag leaf of Triticum aestivum cv. Kalyansona plants showing normal (S + plants) and delayed senescence via removal of spikelets (S? plants). This was done by measurement of metabolites and activities of enzymes such as superoxide dismutase, catalase, guaiacol peroxidase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase. S? plants had higher reduced glutathione/oxidized glutathione (GSH/GSSG) ratio and antioxidant enzyme activities than the control plants and the differences were apparent from 21 days after anthesis (DAA). The removal of the reproductive sink led to an increased antioxidant defense which may be contributing towards the delayed flag leaf senescence in wheat. Chloroplasts and mitochondria, important sources of ROS, were isolated at two stages representing early (7 DAA) and late (21 DAA) senescence. Oxidative damage to proteins was studied in these organelles in relation to SOD and APX. Mitochondria had higher levels of damaged proteins than chloroplasts at 7 DAA in both S+ and S? plants. Higher damage was related to the lower antioxidant enzyme levels of SOD and APX in mitochondria as compared to chloroplasts.  相似文献   

20.
The effects of in vitro exposure of human erythrocytes to different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and its metabolite 2,4-dichlorophenol (2,4-DCP) were studied. The activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the level of reduced glutathione (GSH) were determined. The activity of erythrocyte superoxide dismutase SOD decreased with increasing dose of 2,4-D and 2,4-DCP, while glutathione peroxidase activity increased. 2,4-D (500 ppm) decreased the level of reduced glutathione in erythrocytes by 18% and 2,4-DCP (250 ppm) by 32%, respectively, in comparison with the controls. These results lead to the conclusion that in vitro administration of herbicide-2,4-D and its metabolite 2,4-DCP causes a decrease in the level of reduced glutathione in erythrocytes and significant changes in antioxidant enzyme activities. Comparison of the toxicity of 2,4-D and 2,4-DCP revealed that the most prominent changes occurred in human erythrocytes incubated with 2,4-DCP.  相似文献   

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