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1.
This study was designed to examine if diphenyl diselenide (PhSe) 2, an organoselenium compound, attenuates oxidative stress caused by acute physical exercise in skeletal muscle and lungs of mice. Swiss mice were pre‐treated with (PhSe) 2 (5 mg kg ‐1 day ‐1) for 7 days. At the 7th day, the animals were submitted to acute physical exercise which consisted of continuous swimming for 20 min. The animals were euthanized 1 and 24 h after the exercise test. The levels of thiobarbituric acid reactive species (TBARS), non‐protein thiols (NPSH) and ascorbic acid and the activity of catalase (CAT) were measured in the lungs and skeletal muscle of mice. Glycogen content was determined in the skeletal muscle of mice. Parameters in plasma (urea and creatinine) were determined. The results demonstrated an increase in TBARS levels induced by acute physical exercise in the skeletal muscle and lungs of mice. Animals submitted to exercise showed an increase in non‐enzymatic antioxidant defenses (NPSH and ascorbic acid) in the skeletal muscle. In lungs of mice, activity of CAT was increased. (PhSe) 2 protected against the increase in TBARS levels and ameliorated antioxidant defenses in the skeletal muscle and lungs of mice submitted to physical exercise. These results indicate that acute physical exercise caused a tissue‐specific oxidative stress in the skeletal muscle and lungs of mice. (PhSe) 2 protected against oxidative damage induced by acute physical exercise in mice. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
2.
Acute effects of mercuric chloride (HgCl 2) were evaluated on mice. Mice received a single dose of HgCl 2 (4.6 mg/kg, subcutaneously) for three consecutive days. Thirty minutes after the last injection with HgCl 2, mice received one single injection of 2,3-dimercapto-1-propanesulfonic acid (DMPS) or N-acetylcysteine (NAC) or diphenyl diselenide (PhSe) 2. DMPS, NAC and (PhSe) 2 were utilized as therapy against mercury exposure. At 24 h after the last HgCl 2 injection, blood, liver and kidney samples were collected. δ-Aminolevulinate dehydratase (δ-ALA-D) and Na +, K -+ ATPase activities, thiobarbituric acid-reactive substances (TBARS), non-protein thiols (NPSH) and ascorbic acid concentrations
were evaluated. Plasma aspartate (AST) and alanine (ALT) aminotransferase activities, as well as urea and creatinine levels
were determined. The group of mice exposed to Hg + (PhSe) 2 presented 100% of lethality. Exposure with HgCl 2 caused a decrease on the body weight gain and treatments did not modify this parameter. δ-ALA-D, AST and ALT activities,
TBARS, ascorbic acid levels and NPSH (hepatic and erythrocytic) levels were not changed after HgCl 2 exposure. HgCl 2 caused an increase in renal NPSH content and therapies did not modify these levels. Mice treated with (PhSe) 2, Hg + NAC and Hg + DMPS presented a reduction in plasma NPSH levels. Creatinine and urea levels were increased in mice exposed
to Hg + NAC, while Hg + DMPS group presented an increase only in urea level. Na +, K -+ ATPase activity was inhibited in mice exposed to Hg + DMPS and Hg + NAC. In conclusion, therapies with (PhSe) 2, DMPS and NAC following mercury exposure must be better studied because the formation of more toxic complexes with mercury,
which can mainly damage renal tissue. 相似文献
3.
In this study, the protective effects of diphenyl diselenide [(PhSe) 2] on quinclorac- induced toxicity were investigated in silver catfish ( Rhamdia quelen). The fish were fed for 60 days with a diet in the absence or in the presence of 3.0 mg/Kg (PhSe) 2. Animals were further exposed to 1 mg/L quinclorac for 8 days. At the end of experimental period, fish were euthanized and biopsies from liver and gills, as well as blood samples, were collected. The cortisol and metabolic parameters were determined in plasma, and those enzyme activities related to osmoregulation were assayed in the gills. In liver, some important enzyme activities of the intermediary metabolism and oxidative stress-related parameters, such as thiobarbituric acid-reactive substance (TBARS), protein carbonyl, catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), nonprotein thiols (NPSH) and ascorbic acid contents were also evaluated. Compared to the control group, quinclorac exposure significantly decreased hepatosomatic index and increased cortisol and lactate values in plasma. Moreover, the activities of fructose biphosphatase (FBPase), glucose-6-phosphate dehydrogenase (G6Pase), glycogen phosphorilase (GPase) and aspartate aminotransferase (AST) were significantly increased in liver. Quinclorac also induced lipid peroxidation while the activity of SOD, NPSH and ascorbic acid levels decreased in the liver. However, dietary (PhSe) 2 reduced the herbicide-induced effects on the studied parameters. In conclusion, (PhSe) 2 has beneficial properties based on its ability to attenuate toxicity induced by quinclorac by regulating energy metabolism and oxidative stress-related parameters. 相似文献
4.
AbstractThe antioxidant effect of the ethanolic extract of Hemidesmus indicus R.Br. root (EHI), an indigenous Ayurvedic medicinal plant in India, was studied in rats with ethanol-induced nephrotoxicity. Administering 5 g/kg body weight/day of ethanol for 60 days to male Wistar rats resulted in significantly elevated levels of serum urea, creatinine and uric acid as well as kidney thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LOOH) and conjugated dienes (CD) as compared to those of the experimental control rats. Decreased levels of kidney superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), vitamin C and vitamin E were also observed on alcohol administration as compared with those of the experimental control rats. EHI was administered at a dose of 500 mg/kg body weight/day for the last 30 days of the experiment to rats with ethanol-induced kidney injury, which significantly decreased the levels of serum urea, uric acid and creatinine as well as kidney TBARS, LOOH and CD and significantly elevated the activities of SOD, CAT, GPx, GSH, vitamin C and vitamin E in kidney as compared to that of untreated ethanol-administered rats. Histopathological observations also correlated with the biochemical parameters. Thus, the data indicate that treatment with EHI offers protection against free radical-mediated oxidative stress in kidney of animals with ethanol-induced nephtrotoxicity. 相似文献
5.
We aimed to examine the nucleoside triphosphate diphosphohydrolases (NTPDase) in lymphocytes; adenosine deaminase (ADA) and butyrylcholinesterase (BChE) in serum; and acetylcholinesterase (AChE), superoxide dismutase (SOD), and catalase (CAT) activity in whole blood; since these enzymes are involved in inflammation responses as well as in oxidative stress conditions. We also checked the levels of total thiols (T-SH), non-protein thiols (NPSH), and thiobarbituric acid reactive substances (TBARS) in serum of patients with lung cancer. We collected blood samples from patients ( n = 31) previously treated for lung cancer with chemotherapy. Patients were classified as stage IIIb and IV according to the Union for International Cancer Control (UICC). The results showed a significant increase in the hydrolysis of ATP, ADP, and adenosine in patients when compared with the control group. The activity of AChE, SOD, and CAT as well as the T-SH and NPSH levels were higher in patients group and TBARS levels were lower in patients compared with the control group. These findings demonstrated that the enzymes activity involved in the control of inflammatory and immune processes as well as the oxidative stress parameters are altered in patients with lung cancer. 相似文献
7.
Oxidative stress caused by mercury (Hg) was investigated in Pfaffia glomerata plantlets grown in nutrient solution using sand as substrate. Thirty-day-old acclimated plants were treated for 9 days with four Hg levels (0, 1, 25 and 50 μM) in the substrate. Parameters such as growth, tissue Hg concentration, toxicity indicators (δ-aminolevulinic acid dehidratase, δ-ALA-D, activity), oxidative damage markers (TBARS, lipid peroxidation, and H 2O 2 concentration) and enzymatic (superoxide dismutase, SOD, catalase, CAT, and ascorbate peroxidase, APX) and non-enzymatic (non-protein thiols, NPSH, ascorbic acid, AsA, and proline concentration) antioxidants were investigated. Tissue Hg concentration increased with Hg levels. Root and shoot fresh weight and δ-ALA-D activity were significantly decreased at 50 μM Hg, and chlorophyll and carotenoid concentration were not affected. Shoot H 2O 2 concentration increased curvilinearly with Hg levels, whereas lipid peroxidation increased at 25 and 50 μM Hg, respectively, in roots and shoots. SOD activity showed a straight correlation with H 2O 2 concentration, whereas CAT activity increased only in shoots at 1 and 50 μM Hg. Shoot APX activity was either decreased at 1 μM Hg or increased at 50 μM Hg. Conversely, root APX activity was only increased at 1 μM Hg. In general, AsA, NPSH and proline concentrations increased upon addition of Hg, with the exception of proline in roots, which decreased. These changes in enzymatic and non-enzymatic antioxidants had a significant protective effect on P. glomerata plantlets under mild Hg-stressed conditions. 相似文献
8.
Objectives: This study investigated the potential anti-inflammatory effect of hesperidin against carrageenan induced pleurisy in rat model. Methods: Twenty-four adult female Wistar rats (350 - 450g) were grouped as follows: Group I: rats were administered saline solution only (Normal control group); Group II: rats were administered saline solution (NaCl 0.9%) orally and injected with carrageenan (Inflammation control group); Group III: rats were administered hesperidin only (Hesperidin group); Group IV: rats were administered hesperidin orally and intrapleurally injected with 2% carrageenan (Inflammation treated with hesperidin group). The exudate volume, total leukocyte count, reactive oxygen species (ROS), myeloperoxidase (MPO),δ–aminolevulinate dehydratase (δ-ALA-D), catalase (CAT), superoxide dismutase (SOD), activities as well as non-protein thiol group (NPSH) and thiobarbituric acid reactive substances (TBARS) levels were determined. Results: Pretreatment with hesperidin at a dose of 80 mg/kg orally per day for 21 days, minimized the increase in pleural exudate volume and leucocyte count and modulated the activities of MPO, SOD and CAT, as well as the levels of ROS, NPSH and TBARS in carrageenan-induced rats. Conclusion: Our results suggest that hesperidin can elicit its anti-inflammatory action by blocking exudate and leukocyte influx into pleural cavity, inhibiting MPO activity and preventing oxidative damage. 相似文献
9.
The involvement of non-enzymatic antioxidant defenses in the protective effect of diphenyl diselenide (PhSe) 2 on testicular damage caused by cadmium in mice was investigated. Mice received a single dose of CdCl 2 (5 mg/kg, intraperitoneally). Thirty minutes after the CdCl 2 injection, they received a single oral dose of (PhSe) 2 (400 μmol/kg). Twenty-four hours after CdCl 2 administration, blood samples were collected and mice were killed and had their testes dissected. Parameters in plasma (aspartate (AST) and alanine (ALT) aminotransferases and lactato dehydrogenase (LDH) activities as well as creatinine levels) were determined. The activity of δ-aminolevulinate dehydratase (δ-ALA-D), the levels of thiobarbituric acid-reactive substances (TBARS), ascorbic acid and nonprotein thiols (NPSH) and histological analysis were determined in collected samples. Results demonstrated that (PhSe) 2 protected against toxicity induced by CdCl 2 on δ-ALA-D activity, ascorbic acid and NPSH levels. (PhSe) 2 protected against the increase in plasma AST, ALT and LDH activities caused by CdCl 2. Testes of mice exposed to CdCl 2 showed marked histopathological alterations that were ameliorated by administration of (PhSe) 2. (PhSe) 2 protected against toxicity induced by CdCl 2 in testes of mice. Ascorbic acid and NPSH, non-enzymatic antioxidant defenses, are involved in the protective effect of (PhSe) 2 against testicular damage caused by CdCl 2 in mice. 相似文献
10.
Dendritic cells (DCs) are antigen-presenting cells (APCs) capable of capturing haptens and to process and present them to T lymphocytes. In order to sensitize T cells for contact hypersensitivity (CHS), skin DCs suffer a maturation process with modifications on their surface molecules. The aim of this work was to evaluate changes induced by two contact sensitizers, 2,4-dinitrofluorobenzene (DNFB) and nickel sulfate (NiSO 4), and a non-sensitizer 2,4-dichloronitrobenzene (DCNB), on the protein levels of two activation markers, CD40 and IL-12 receptor (IL-12R), in a mouse skin dendritic cell line (FSDC). The expression of CD40 and IL-12R proteins was evaluated by western blot assay and direct immunofluorescence microscopy. The results showed that CD40 and IL-12R expression increased significantly after cell exposure to NiSO 4 and DNFB, although DNFB exhibited a stronger activity. There was no effect with DCNB. The epidermal cytokine granulocyte–macrophage colony-stimulating factor (GM-CSF), also used in the experiments, slightly increased the expression of both CD40 and IL-12R and when tested together with the sensitizers the effect was partially additive. The results suggest that the sensitizers DNFB and NiSO 4 are directly involved on the changes of the surface markers CD40 and IL-12R in skin DCs, during the sensitization phase of CHS, and this effect may be enhanced by GM-CSF. In contrast, no effect was observed with DCNB. 相似文献
11.
Neopterin and the reduced form, 7,8-dihydroneopterin (78NP), are pteridines released from macrophages when stimulated with γ-interferon in vivo. The role of 78NP in inflammatory response is unknown though neopterin has been used clinically as a marker of immune cell activation, due to its very fluorescent nature. Using red blood cells as a cellular model, we demonstrated that micromolar concentrations of 78NP can inhibit or reduce red blood cell haemolysis induced by 2,2′-azobis(amidinopropane)dihydrochloride (AAPH), hydrogen peroxide, or hypochlorite. One hundred μM 78NP prevented HOCl haemolysis using a high HOCl concentration of 5 μmole HOCl/10 7 RBC. Fifty μM 78NP reduced the haemolysis caused by 2 mM hydrogen peroxide by 39% while the same 78NP concentration completely inhibited haemolysis induced by 2.5 mM AAPH. Lipid peroxidation levels measured as HPLC-TBARS were not affected by addition of 78NP. There was no correlation between lipid oxidation and cell haemolysis suggesting that lipid peroxidation is not essential for haemolysis. Conjugated diene measurements taken after 6 and 12 hour exposure to hydrogen peroxide support the TBARS data. Gel electrophoresis of cell membrane proteins indicated 78NP might inhibit protein damage. Using dityrosine as an indicator of protein damage, we demonstrated 200 μM 78NP reduced dityrosine formation in H 2O 2/Fe ++ treated red blood cell ghosts by 30%. HPLC analysis demonstrated a direct reaction between 78NP and all three oxidants. Two mM hydrogen peroxide oxidised 119 nM of 78NP per min while 1 mM AAPH only oxidised 50 nM 78NP/min suggesting that 78NP inhibition of haemolysis is not due to 78NP scavenging the primary initiating reactants. In contrast, the reaction between HOCl and 78NP was near instant. AAPH and hydrogen peroxide oxidised 78NP to 7,8-dihydroxanthopterin while hypochlorite oxidation produced neopterin. The cellular antioxidant properties of 78NP suggest it may have a role in protecting immune cells from free radical damage during inflammation. 相似文献
12.
Extremes of temperature (both heat and chilling) during early inbibitional phase of germination caused disruption of redox-homeostasis by increasing accumulation of reactive oxygen species (superoxide and hydrogen peroxide) and significant reduction of antioxidative defense (assessed in terms of total thiol content and activities of superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase) in germinating tissues of rice ( Oryza sativa L., cultivar Ratna). Imbibitional heat and chilling stress also induced oxidative damage to newly assembled membrane system by aggravating membrane lipid peroxidation and protein oxidation [measured in terms of thiobarbituric acid reactive substances (TBARS), free carbonyl content (C = O groups) and membrane protein thiol level (MPTL)]. Treatment with standardized low titer hydrogen peroxide during early imbibitional phase of germination caused significant reversal in oxidative damages to the newly assembled membrane system imposed by heat and chilling stress [evident from the data of TBARS, C = O, MPTL, ROS accumulation, membrane permeability status, membrane injury index and oxidative stress index] in seedlings of experimental rice cultivar. Imbibitional H 2O 2 pretreatment also caused up-regulation of antioxidative defense (activities of superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase and total thiol content) in the heat and chilling stress-raised rice seedlings. When the parameters of early growth performances were assessed (in terms of relative growth index, biomass accumulation, relative germination performance, mean daily germination, T 50 value), it clearly exhibited significant improvement of early growth performances of the experimental rice cultivar. The result proposes that an ‘inductive pulse’ of H 2O 2 is required to switch on some stress acclimatory metabolism through which plant restores redox homeostasis and prevents or repairs oxidative damages to newly assembled membrane system caused by unfavorable environmental cues during early germination to the rice cultivar Ratna. The importance of mitigating oxidative damages to membrane lipid and protein necessary for post-germinative growth under extremes of temperature is also suggested. 相似文献
13.
A recent report (Radi et al., J. Biol. Chem. 266:22028–22034, 1991) showed that rat heart mitochondria contain catalase. The protective role of mitochondrial catalase was tested by exposing heart or kidney mitochondria and mitoplasts to two oxidants (H 2O 2) or tert-butyl hydroperoxide, t-BOOH), estimating lipid peroxidation (as thiobarbituric acid-reactive substances, TBARS) and overall oxidative stress (as chemiluminescence). Additional controls included heart and kidney preparations from aminotriazole-treated (catalase-depleted) rats. Both oxidants increased TBARS in catalase-free preparations to similar extents over their respective controls (between 200 to 350%). In catalase-containing preparations, H 2O 2 lipid peroxidation increased by only 40 to 96% over controls. Similar qualitative results were obtained when measuring chemiluminescence. The catalytic role of cytochrome c in mitochondrial lipid peroxidation was investigated by exposing either control or cytochrome- c-depleted kidney mitoplasts (catalase free) to either H 2O 2 or t-BOOH. Hydrogen-peroxide-dependent mitochondrial lipid peroxidation varied with cytochrome c concentrations, remaining close to controls when cytochrome c concentration decreased by 66%, even though there was no catalase present. Tert-butyl hydroperoxide-dependent lipid peroxidation was less affected by cytochrome c remaining 2.3-fold above controls under the same conditions, suggesting that organic peroxides are more likely to remain in the less polar membrane environment being decomposed by heme or nonheme iron imbedded in the inner mitochondrial membrane. Chemiluminescence was less affected by cytochrome c depletion. Comparing control and cytochrome- c-deficient mitochondria, chemiluminescence was 1.7-fold and 2.8-fold higher when control preparations were challenged with t-BOOH or H 2O 2, respectively. 相似文献
14.
In this study, we investigated the effect of diphenyl ditelluride (PhTe) 2 administration (10 and 50?μmol/kg) on adult mouse behavioral performance as well as several parameters of oxidative stress in the brain and liver. Adult mice were injected with (PhTe) 2 or canola oil subcutaneously (s.c.) daily for 7?days. Results demonstrated that (PhTe) 2 induced prominent signs of toxicity (body weight loss), behavioral alterations and increased in lipid peroxidation in brain. 50?μmol/kg (PhTe) 2 inhibited blood δ-aminolevulinic acid dehydratase (δ-ALA-D), a redox sensitive enzyme. (PhTe) 2 caused an increase in cerebral non-protein thiol (NPSH) and protein thiol (PSH) groups. In the liver, 50?μmol/kg (PhTe) 2 decreased NPSH, but did not alter the content of protein thiol groups. (PhTe) 2 decreased cerebral antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GPx), and thioredoxin reductase (TrxR). In liver, (PhTe) 2 increase SOD and GR and decreased GPx activity. Results obtained herein suggest that the brain was more susceptible to oxidative stress induced by (PhTe) 2 than the liver. Furthermore, we have demonstrated for the first time that TrxR is an in vivo target for (PhTe) 2. Combined, these results highlight a novel molecular mechanism involved in the toxicity of (PhTe) 2. In particular the inhibition of important selenoenzymes (TrxR and GPx) seems to be involved in the neurotoxicity associated with (PhTe) 2 exposure in adult mice. 相似文献
15.
Gibberellic acid (GA 3) promotes and continuous gold light inhibits germination of seeds of a dwarf strain (WB-2) of watermelon [ Citrullus lanatus (Thunb.) Matsu. and Nakai]. Osmotic inhibition of germination with mannitol in light-grown seeds of WB-2 was only slightly reversed by GA 3 at the concentrations used, whereas, GA 3 substantially relieved osmotic inhibition in dark-grown seeds. The effects of GA3 and gold light on development of catalase and invertase activities and on levels of free amino acids in germinating seeds of WB-2 were examined. Light depressed development of catalase and invertase activity. Levels of free amino acids increased more slowly in embryonic axes of light- than dark-incubated seeds, but in cotyledons higher levels of amino acids were maintained in light-grown seeds. GA3 accelerated the development of catalase activity in whole embryos and invertase activity in embryonic axes, but did not significantly affect invertase activity in cotyledons during germination. GA3 had little effect on amino acid pools in cotyledons and embryonic axes. 相似文献
16.
BackgroundReactive oxygen species (ROS)-mediated cancer therapeutic has been at higher appreciation than those mediated by reactive nitrogen species. Cytotoxic mechanism of a novel nitric oxide (NO) inducing-Pt coated Au nanoparticle (NP) has been comparatively studied with the well-established ROS inducing Pt-based anticancer drug cisplatin in human lung A549 carcinoma cells. MethodsCytotoxicity was evaluated by MTT assay, lactate dehydrogenase (LDH) release, thiobarbituric acid substances (TBARS) and C11-Boron dipyrromethene (BODIPY). ROS (O 2·− and H 2O 2) was measured with dihydroethidium (DHE) and H 2O 2-specific sensor. Nitric oxide (NO) and mitochondrial dysfunction were evaluated respectively by NO-specific probe DAR-1 and JC-1. Autophagy was determined by lysotracker (LTR) and monodansylcadaverine (MDC) applied tandemly whereas apoptosis/necrosis by Hoechst/PI and caspase 3 activity. ResultsIC50 (concentration that inhibited cell viability by 50%) of Pt coated Au NP came to be 0.413 μM whereas IC50 of cisplatin came out to 86.5 μM in A549 cells treated for 24 h meaning NPs toxicity was over 200 times higher than cisplatin. However, no significant stimulation of intracellular ROS was observed at the IC50 of Pt coated Au NPs in A549 cells. However, markers like LDH release, TBARS, BODIPY and ROS were significantly higher due to cisplatin in comparison to Pt coated Au NP. ConclusionsPt coated Au NP caused NO-dependent mitochondrial dysfunction and autophagy. Mode of cell death due to NP was much different from ROS-inducing cisplatin. General significancePt coated Au NP offer promising opportunity in cancer therapeutic and warrants advanced study in vivo models of cancer. 相似文献
17.
Methylmalonic acidemia is a genetic disease characterized by accumulation of organic acids, such as methylmalonic (MMA) and malonic (MA) acids. Considering that the accumulation of MMA and MA causes several damages due to oxidative stress, antioxidants are thought to play a pivotal role in preventing deleterious effects associated with exposure to such compounds. Ilex paraguariensis (IP) was used here to test the hypothesis that supplementation with the aqueous extract of this plant could exert protective effect against MMA or MA induced mortality, behavioral and/or biochemical changes in Drosophila melanogaster (DM). Initially, a curve time- and dose–response to MMA (1–10 mM), MA (1–10 mM) and IP (63–500 μM) was performed. Thereafter, flies were concomitantly exposed to MA (5 mM), MMA (5 mM) and/or IP (250 μg/mL) during 15 days for survival assay, and for 48 hs to MA (1 or 5 mM), MMA (1 or 5 mM) and/or IP (250 μg/mL) for subsequent investigations. Both MMA and MA exposure resulted in higher incidence of mortality, a worse performance in the negative geotaxis assay and increased locomotion in open-field test as compared with control group. Furthermore, a marked increase in non-protein thiol (NPSH) and in thiobarbituric acid reactive substances (TBARS) levels, decrease in superoxide dismutase (SOD), catalase and acetylcholinesterase (AChE) activities, and decrease in MTT and resazurin reduction were noted in MMA or MA treated groups. IP treatment offered significant protection against all alterations associated to MMA or MA exposure. This study confirm the hypothesis that supplementation with IP offers protection against changes associated to MMA or MA exposure in DM, due, at least in part, to its antioxidant effect. 相似文献
18.
Seedlings of rice ( Oryza sativa L.) cv. Pant-12 grown in sand cultures containing 200 and 400 μM NiSO 4, showed a decrease in length and fresh weight of roots and shoots. Nickel was readily taken up by rice seedlings and the
concentration was higher in roots than shoots. Nickel-treated seedlings showed increased rates of superoxide anion (O 2
•−
) production, elevated levels of H 2O 2 and thiobarbituric acid reactive substances (TBARS) demonstrating enhanced lipid peroxidation, and a decline in protein thiol
levels indicative of increased protein oxidation compared to controls. With progressively higher Ni concentrations, non-protein
thiol and ascorbate (AsA) increased, whereas the level of low-molecular-weight thiols (such as glutathione and hydroxyl-methyl
glutathione), the ratio of these thiols to their corresponding disulphides, and the ratio of AsA to dehydroascorbic acid declined
in the seedlings. Among the antioxidant enzymes studied, the activities of all isoforms of superoxide dismutase (Cu-Zn SOD,
Mn SOD and Fe SOD), guaiacol peroxidases (GPX) and ascorbate peroxidase (APX) increased in Ni-treated seedlings, while no
clear alteration in catalase activity was evident. Activity of the ascorbate-glutathione cycle enzymes monodehydroascorbate
reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR)—significantly increased in Ni-treated
seedlings. However such increase was apparently insufficient to maintain the intracellular redox balance. Results suggest
that Ni induces oxidative stress in rice plants, resulting in enhanced lipid peroxidation and decline in protein thiol levels,
and that (hydroxyl-methyl) glutathione and AsA in conjunction with Cu-Zn SOD, GPX and APX are involved in stress response. 相似文献
19.
The non-protein sulfhydryl (NPSH) content of cells moving into S from G 1, plateau phase G 1, and G 0 was measured. Chinese hamster ovary (CHO) cells accumulated in G 1 by growth into plateau phase contain only one-fourth the NPSH concentration of cycling C 1 cells or G 1 cells accumulated by brief growth in isoleucine-deficient medium. Upon dilution of plateau cultures with fresh medium, cellular NPSH content increases rapidly, reaching the same level as that in cycling cells within four hours. This increase is prevented by cycloheximide but not by actinomycin D or hydroxyurea. Neither CHO cells cycling in vitro nor salivary gland G 0 cells stimulated with isoproterenol in vivo show significant changes in intracellular NPSH concentrations during S phase. This suggests that the concentration of intracellular NPSH (glutathione) remains constant during the cell cycle except when cells are grown to plateau phase in exhausted or deficient medium, in which case normal degradation exceeds synthesis and the gross level falls until fresh medium is provided and synthesis, apparently on preexisting RNA templates, accelerates. 相似文献
20.
Parkin mutations produce Parkinson’s disease (PD) in humans and nigrostriatal dopamine lesions related to increased free radicals in mice. We examined the effects of NP7, a synthetic, marine derived, free radical scavenger which enters the brain, on H 2O 2 toxicity in cultured neurons and glia from wild-type (WT) and parkin null mice (PK-KO).NP7, 5-10 μM, prevented the H 2O 2 induced apoptosis and necrosis of midbrain neuronal and glial cultures from WT and PK-KO mice. NP7 suppressed microglial activation and the H 2O 2 induced drop-out of dopamine neurons . Furthermore, NP7 prevented the increased phosphorylation of ERK and AKT induced by H 2O 2. NP7 may be a promising neuroprotector against oxidative stress in PD. 相似文献
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