Regulation of H+Pumping by Plant Plasmalemma under Osmotic Stress: The Role of 14-3-3 Proteins

All higher plants have high-specific sites for binding fusicoccin (FCBS), a metabolite of the fungus Fusicoccum amygdaliDel. These sites are localized on the plasmalemma and produced by the association of the dimers of 14-3-3 proteins with the C-terminal autoinhibitory domain of H⁺-ATPase. Considering the fusicoccin binding to the plasmalemma as an index characterizing the formation of this complex, we studied the influence of osmotic stress on the interaction between 14-3-3 proteins and H⁺-ATPase in the suspension-cultured sugar beet cells and protoplasts obtained from them. An increase in the osmolarity of the extracellular medium up to 0.3 Osm was shown to enhance proton efflux from the cells by several times. The number of FCBS in isolated plasma membranes increased in parallel, whereas 14-3-3 proteins accumulated in this membrane to a lesser degree. The amount of H⁺-ATPase molecules did not change, and the ATP-hydrolase activity changed insignificantly. The data obtained indicate that osmotic stress affects H⁺-ATPase pumping in the plasmalemma through its influence on the coupling between H⁺-transport and ATP hydrolysis; 14-3-3 proteins are involved in this coupling. The interaction between the plasmalemma and the cell wall is suggested to be very important in this process.     

灵武长枣果实质膜和液泡膜H~+-ATPase和H~+-PPase活性与果实糖分积累

以不同发育时期灵武长枣(Ziziphus jujuba cv.Lingwuchangzao)的果实为材料,通过测定与分析果肉组织中细胞质膜、液泡膜H+-ATPase和H+-PPase活性、果实糖分含量变化,研究了灵武长枣果实质膜、液泡膜H+-ATPase和H+-PPase活性与糖积累特性的关系。结果表明:(1)果实第二次快速生长期之前主要积累葡萄糖和果糖,之后果实迅速积累蔗糖,葡萄糖和果糖含量则逐渐下降,成熟期果实主要积累蔗糖。(2)在果实发育的缓慢生长期S1,质膜H+-ATPase活性最低;第一次快速生长期,质膜H+-ATPase活性最高;缓慢生长期S2,其活性降低;第二次快速生长期,质膜H+-ATPase活性升至次高;完熟期,质膜H+-ATPase活性下降幅度较大。(3)在果实发育过程中,液泡膜H+-ATPase和H+-PPase活性的变化趋势相似。缓慢生长期S1,液泡膜H+-ATPase和H+-PPase活性较低;从缓慢生长期S1至第一次快速生长期缓慢下降至最低;从第一次快速生长期开始,液泡膜H+-ATPase和H+-PPase活性呈现为逐渐增高的变化趋势;除第二次快速生长期以外,液泡膜H+-PPase活性始终高于H+-ATPase。由此推测,质膜H+-ATPase和液泡膜H+-ATPase、H+-PPase对灵武长枣果实糖分的跨膜次级转运起到重要的调控作用。     

Functional changes in bladder tissue from type III collagen-deficient mice

The present work investigates the protective effects of N-acetylcysteine (NAC) on carbofuran-induced alterations in lipid composition and activity of membrane bound enzymes (Na⁺-K⁺-ATPase and Ca²⁺-ATPase) in the rat brain. Animals were exposed to carbofuran at a dose of 1 mg/kg body weight, orally, for a period of 28 days. A significant increase in lipid peroxidation in terms of TBARS was observed in brain after carbofuran exposure. NAC administration (200 mg/kg body weight) on the other hand lowered the carbofuran-induced lipid peroxidation to near normal. The increased lipid peroxidation following carbofuran exposure was accompanied by a significant decrease in the levels of total lipids, which is attributed to the reduction in phospholipid levels. Furthermore, NAC administration had a beneficial effect on carbofuran-induced alterations in lipid composition. The ratio of cholesterol to phospholipid, a major determinant of membrane fluidity, was increased in response to carbofuran exposure. This was associated with decreased activity of Na⁺-K⁺-ATPase and Ca²⁺-ATPase. NAC was observed to offer protection by restoring the cholesterol to phospholipid ratio along with the activity of Na⁺-K⁺-ATPase and Ca²⁺-ATPase. The results clearly suggest that carbofuran exerts its neurotoxic effects by increasing lipid peroxidation, altering lipid composition and activity of membrane bound enzymes. NAC administration ameliorated the effects of carbofuran suggesting its potential therapeutic effects in carbofuran neurotoxicity.     

Effects of salt-adaptation and salt-stress on extracellular acidification and microsome phosphohydrolase activities in tomato cell suspensions

The effects of NaCl-adaptation and NaCl-stress on in vivo H⁺ extrusion and microsomal vanadate- and bafilomycin-sensitive ATPase and PPase activities were studied in tomato cell suspensions. Acidification of the external medium by 50 mM NaCl-adapted and non-adapted (control) tomato cells was similar. Extracellular acidification by both types of cells during the first hour of incubation with 2 μM fusicoccin (FC) in the presence of 100 mM NaCl was lightly increased while in the presence of 100 mM KCl it was increased by 3 (control)- and 6.5 (adapted)-fold. Extracellular alkalinization after 2 h of cell incubation in 100 mM NaCl indicated the possibility that a Na⁺/H⁺ exchange activity could be operating in both types of cells. Moreover, acidification induced by adding 100 mM NaCl + FC to non-adapted cells was relatively less affected by vanadate than that induced by 5 mM KCl + FC, which suggested that salt stress could induce some component other than H⁺ extrusion by H⁺-ATPase. In addition, no differences were observed in microsomal vanadate-sensitive ATPase activity among control, NaCl-adapted and NaCl-stressed cells, while K⁺-stimulated H⁺-PPase and bafilomycin-sensitive H⁺-ATPase activities were higher in microsomes from NaCl-adapted than in those from control cells. Likewise, the stimulation of in vivo H⁺ extrusion in NaCl adapted cells under NaCl or KCl stress in the presence of FC occurred with an inhibition of H⁺-PPase and bafilomycin-sensitive H⁺-ATPase activities and without changes in the vanadate-sensitive H⁺-ATPase activity. These results suggest that the stimulation of tonoplast proton pumps in NaCl-adapted cells, without changes in plasmalemma H⁺-ATPase, could serve to energize Na⁺ efflux across the plasmalemma and Na⁺ fluxes into vacuoles catalyzed by the Na⁺/H⁺ antiports. This revised version was published online in June 2006 with corrections to the Cover Date.     

In vivo and in vitro effects of copper and cadmium on the plasma membrane H+-ATPase from cucumber (Cucumis sativus L.) and maize (Zea mays L.) roots

The plasmalemma vesicles isolated from cucumber and maize roots were used to study the effect of Cu²⁺ and Cd²⁺ on the hydrolytic and proton pumping activities of ATPase. In vivo application of metal ions to the plant growth solutions resulted in stimulation of the proton transport in maize. In cucumber roots the action of metals was not the same: cadmium stimulated the H⁺ transport through plasmalemma whereas Cu²⁺ almost completely inhibited it. Copper ions decreased the hydrolytic activity of H⁺-ATPase in cucumber, without any effect on this activity in membranes isolated from maize roots. The effect of cadmium on the hydrolytic activities was opposite: ATP-hydrolysis activity in plasmalemma was not altered in cucumber, whereas in maize its stimulation was observed. The amount of accumulated metals was not the main reason of different influence of metals on H⁺-ATPase activity in tested plants. In in vitro experiments Cu²⁺ inhibited H⁺ transport in the cucumber, to a higher degree than Cd²⁺ and both metals did not change this H⁺-ATPase activity of plasmalemma isolated from corn roots. Cu²⁺ added into the incubation medium reduced the hydrolytic activity of ATPase in the plasma membrane isolated from cucumber as well as from corn roots. Cd²⁺ diminished the hydrolytic activity of ATPase in cucumber, and no effect of Cd²⁺ in the plasmalemma isolated from corn roots was found. Our results indicated different in vitro and in vivo action of both metals on H⁺-ATPase and different response of this enzyme to Cu²⁺ and Cd²⁺ in maize and cucumber.     

Effect of soil salinity, soil drought, and their combined action on the biochemical characteristics of cotton roots

Stress caused by soil salinity and soil drought limits cotton productivity in China. To determine the tolerance levels of cotton, we assessed the effects of soil salinity and soil drought on the biochemical characteristics of the roots of two cotton cultivars (CCRI-44, salt-tolerant; Sumian 12, salt-sensitive). Specifically, we analyzed root biomass, fatty acid composition, antioxidative enzyme activity, lipid peroxidation, H⁺-ATPase and Ca²⁺-ATPase activities. The cotton root biomass of the two cultivars declined significantly under conditions of soil salinity, soil drought, and the two stressors combined. The antioxidant enzyme activity of the roots also decreased markedly, which caused lipid peroxidation to increase, and changed the composition of the fatty acid membrane. H⁺-ATPase, Ca²⁺-ATPase and antioxidant enzyme activity decreased more under the two stressors combined. However, H₂O₂ content and O₂ ^? generation increased under the two stressors combined, compared to each stressor separately. Overall, the combination of soil salinity and drought has a greater inhibitory effect and more harmful impact on root growth than each stressor separately. The higher tolerance of CCRI-44 to soil salinity and drought stress than Sumian 12 might be explained by differences in cotton root antioxidative enzyme activity. The lipid peroxidation levels of cotton roots might represent an important biochemical trait for stress tolerance.     

Effect of salicylic acid on the proton translocation activity of plasmalemma of potato tuber cells

Action of salicylic acid (SA) on the activity of membrane bound H⁺-ATPase and passive proton permeability of plasmalemma membrane vesicles (PMV) from parenchyma cells of potato tubers was detected. A correlation between SA action on germination of tubers and activity of plasmalemma H⁺-ATPase was revealed: the application of growth-stimulating concentrations of SA (10⁻¹⁰–10⁻⁸ M) in the system in vitro resulted in activation of plasmalemma H⁺-ATPase, while the use of growth-inhibiting concentrations (10⁻⁴, 10⁻⁵ M) provoked inhibition of the enzyme activity. Addition of jasmonic acid (JA) to the incubation mix resulted in increase of SA effect on the accumulation of H⁺ in PMV.     

Changes in plasma membrane lipids, aquaporins and proton pump of broccoli roots, as an adaptation mechanism to salinity

Salinity stress is known to modify the plasma membrane lipid and protein composition of plant cells. In this work, we determined the effects of salt stress on the lipid composition of broccoli root plasma membrane vesicles and investigated how these changes could affect water transport via aquaporins. Brassica oleracea L. var. Italica plants treated with different levels of NaCl (0, 40 or 80 mM) showed significant differences in sterol and fatty acid levels. Salinity increased linoleic (18:2) and linolenic (18:3) acids and stigmasterol, but decreased palmitoleic (16:1) and oleic (18:1) acids and sitosterol. Also, the unsaturation index increased with salinity. Salinity increased the expression of aquaporins of the PIP1 and PIP2 subfamilies and the activity of the plasma membrane H⁺-ATPase. However, there was no effect of NaCl on water permeability (P_f) values of root plasma membrane vesicles, as determined by stopped-flow light scattering. The counteracting changes in lipid composition and aquaporin expression observed in NaCl-treated plants could allow to maintain the membrane permeability to water and a higher H⁺-ATPase activity, thereby helping to reduce partially the Na⁺ concentration in the cytoplasm of the cell while maintaining water uptake via cell-to-cell pathways. We propose that the modification of lipid composition could affect membrane stability and the abundance or activity of plasma membrane proteins such as aquaporins or H⁺-ATPase. This would provide a mechanism for controlling water permeability and for acclimation to salinity stress.     

Effect of melafen on the function of endoplasmic reticulum and plasmalemmal H<Superscript>+</Superscript>-atpase in the regulation of growth processes in potato tubers

The mechanism of the stimulatory effect of melafen on potato tuber sprouting was studied. The treatment with 10^?8 M melafen intensified division and stretching and activated granular endoplasmic reticulum of apical meristem cells. An increase in the activity of membrane-bound H⁺-ATPase in the plasmalemma of parenchymal cells of melafen-treated potato tubers and enhancement of passive proton permeability of the plasmalemma was observed. In vitro studies showed that melafen at concentrations of 10^?5?10^?12 M stimulated the activity of plasmalemmal H⁺-ATPase in a concentration-dependent manner.     

Response of the plant root to aluminum stress: Analysis of the inhibition of the root elongation and changes in membrane function

Pea root elongation was strongly inhibited in the presence of a low concentration of Al (5 μM). In Al-treated root, the epidermis was markedly injured and characterized by an irregular layer of cells of the root surface. Approximately 30% of total absorbed Al accumulated in the root tip and Al therein was found to cause the inhibition of whole root elongation. Increasing concentrations of Ca²⁺ effectively ameliorated the inhibition of root elongation by Al and 1 mM of CaCl₂ completely repressed the inhibition of root elongation by 50 μM Al. The ameliorating effect of Ca²⁺ was due to the reduction of Al uptake. H⁺-ATPase and H⁺-PPase activity as well as ATP and PPidependent H⁺ transport activity of vacuolar membrane vesicles prepared from barley roots increased to a similar extent by the treatment with 50 μM AlCl₃. The rate of increase of the amount of H⁺-ATPase and H⁺-PPase was proportional to that of protein content measured by immunoblot analysis with antibodies against the catalytic subunit of the vacuolar H⁺-ATPase and H⁺-PPase of mung bean. The increase of both activities was discussed in relation to the physiological tolerance mechanism of barley root against Al stress.     

Nitric oxide enhances salt tolerance in maize seedlings through increasing activities of proton-pump and Na+/H+ antiport in the tonoplast

Nitric oxide (NO), an endogenous signaling molecule in animals and plants, mediates responses to abiotic and biotic stresses. Our previous work demonstrated that 100 μM sodium nitroprusside (SNP, an NO donor) treatment of maize seedlings increased K⁺ accumulation in roots, leaves and sheathes, while decreasing Na⁺ accumulation (Zhang et al. in J Plant Physiol Mol Biol 30:455–459, 2004b). Here we investigate how NO regulates Na⁺, K⁺ ion homeostasis in maize. Pre-treatment with 100 μM SNP for 2 days improved later growth of maize plants under 100 mM NaCl stress, as indicated by increased dry matter accumulation, increased chlorophyll content, and decreased membrane leakage from leaf cells. An NO scavenger, methylene blue (MB-1), blocked the effect of SNP. These results indicated that SNP-derived NO enhanced maize tolerance to salt stress. Further analysis showed that NaCl induced a transient increase in the NO level in maize leaves. Both NO and NaCl treatment stimulated vacuolar H⁺-ATPase and H⁺-PPase activities, resulting in increased H⁺-translocation and Na⁺/H⁺ exchange. NaCl-induced H⁺-ATPase and H⁺-PPase activities were diminished by MB-1. 1-Butanol, an inhibitor of phosphatidic acid (PA) production by phospholipase D (PLD), reduced NaCl- and NO-induced H⁺-ATPase activation. In contrast, applied PA stimulated H⁺-ATPase activity. These results suggest that NO acts as a signal molecule in the NaCl response by increasing the activities of vacuolar H⁺-ATPase and H⁺-PPase, which provide the driving force for Na⁺/H⁺ exchange. PLD and PA play an important role in this process.     

Asymmetric distribution of the plasma-membrane H+-ATPase in embryos of Vicia faba L. with special reference to transfer cells

The ultrastructural localization of the plasma-membrane H⁺ -ATPase by immunocytochemistry was studied in Vicia faba embryos which absorb nutrients from the maternal organism through the transfer cells of their external epidermis. The samples were embedded in LR White resin and the specificity of immunolabelling was checked by inhibition in the presence of purified H⁺-ATPase. The following results were obtained: (i) The H⁺-ATPase density varied according to the cell type, being higher in transfer cells than in other cell types, especially the non-modified cells of the internal epidermis. (ii) There was a marked polarity in transfer cells as proton pumps were more numerous in the area of plasmalemma infoldings where active nutrient uptake is assumed to take place, (iii) No clear immunolabelling occurred on the plasma membrane of plasmodesmata. These results demonstrate that in transfer cells the area of plasmalemma infoldings is highly specialized for active solute transport; they also support the idea of specific structural properties of the plasmalemma in plasmodesmata.This work was supported by the Centre National de la Recherche Scientifique (URA CNRS 574). We express our gratitude to Dr M.G. Palmgren (Royal Veterinary and Agricultural University, Copenhagen, Denmark) for his gift of purified H⁺-ATPase. We wish to thank J.C. Fromont for his skillful technical assistance with the immunological procedures. We are grateful to J.M. Perault and C. Besse of the Electron Microscopy Service (Service Universitaire de Microscopie Electronique Appliquée à la Biologie Poitiers, France) for their contribution to the microscopical techniques.     

Drought stress stimulates p-nitrophenyl phosphate hydrolysis rate of the plasma membrane H+-ATPase from wheat leaves

The influence of drought stress on the ATP and p-nitrophenyl phosphate (PNPP) hydrolysis activity by plasma membrane H⁺-ATPase was investigated using purified plasma membrane vesicles from wheat leaves by two-phase partitioning. Drought stress increased the ATPase activity, and the optimal pH was shifted from 6.5 to about 7.0. Drought stress also stimulated the PNPP hydrolysis rate. The K_m for PNPP hydrolysis was moved from 4.49 ± 0.33 mM to 3.64 ± 0.12 mM. In addition, the PNPP hydrolysis was more sensitive to vanadate under drought compared to the control. However, the inhibitory effect of hydroxylamine on the ATPase was not changed by the present drought stress. In addtion, drought stress also decreased the trypsin activation of PNPP hydrolysis by PM H⁺-ATPase. These results suggested that drought stress altered the catalytic mechanism of the plasma membrane H⁺-ATPase, and the stimulation of its activity by drought stress was mainly due to increase of the catalytic activity of its phosphatase domain. It is also suggested that drought stress might alter the structure or property of the C-terminal end of PM H⁺-ATPase, therefore increasing the catalytic activity of the phosphatase domain.     

Alteration of plasmalemma H<Superscript>+</Superscript>-ATPase activity in maize coleoptile cells at different age of seedlings

An irregular alteration of the activity and character of the distribution of plasmalemma H⁺-ATPase has been shown in parenchymal cells of the coleoptile subapical zone within the period from the third to fifth day of ethiolated maize seedling development. The study was carried out by the cytochemical method. The highest enzyme activity was determined in the cells of four-day-old coleoptiles. The revealed change in H⁺-ATPase activity does not correspond to the dynamics of the growth intensity of the elongation of coleoptile cells within the studied period of seedling development.     

Inhibition of Na(+),K(+)-ATPase activity in hippocampus of rats subjected to acute administration of homocysteine is prevented by vitamins E and C treatment

In the present study we evaluated the effect of acute homocysteine (Hcy) administration on Na⁺,K⁺-ATPase activity, as well as on some parameters of oxidative stress such as total radical-trapping antioxidant potential (TRAP) and on activities of antioxidant enzymes catalase (CAT), superoxide dismutase and glutathione peroxidase in rat hippocampus. Results showed that Hcy significantly decreased TRAP, Na⁺,K⁺-ATPase and CAT activities, without affecting the activities of superoxide dismutase and glutathione peroxidase. We also verified the effect of chronic pretreatment with vitamins E and C on the reduction of TRAP, Na⁺,K⁺-ATPase and CAT activities caused by Hcy. Vitamins E and C per se did not alter these parameters, but prevented the reduction of TRAP, Na⁺,K⁺-ATPase and CAT activities caused by Hcy. Our results indicate that oxidative stress is probably involved in the pathogenesis of homocystinuria and that reduction of Na⁺,K⁺-ATPase activity may be related to the neuronal dysfunction found in homocystinuric patients.     

Modulations of rabbit erythrocyte ATPase activities induced by in vitro and in vivo exposure to ethanol

Alcohol intake is associated with numerous degenerative disorders, and the detrimental effects of alcohol may be due to its influence on plasma membrane and cellular transport systems. The aim of the present study was to compare in vitro and in vivo effects of ethanol on rabbit erythrocyte ATPase activities and correlate them with ethanol-induced oxidative stress. Age-matched male rabbits were given 5% ethanol in 2% sucrose solution, for 6 weeks ad libitum; control animals were given tap water. Daily intake of ethanol was 5 g/kg body weight; this experimental regimen resulted in an average serum ethanol concentration of 16.77 ± 2.00 mM/l. After this period, blood was collected, serum ethanol concentration was determined and erythrocyte membranes were prepared according to the method of Post et al. Activities of Na⁺/K⁺- and Mg²⁺-ATPases were determined. Thiobarbituric acid-reactive substance (TBARS) assay was used to detect levels of lipid peroxidation, a major indicator of oxidative stress. In vitro ethanol inhibits both Na⁺/K⁺-ATPase and Mg²⁺-ATPase, but Na⁺/K⁺-ATPase is more sensitive to the ethanol-induced inhibition. Increasing concentration of ethanol increased TBARS production, but significant difference was attained only at 5 and 12.5 mM of ethanol. Chronic ethanol consumption induced significant increase in Na⁺/K⁺- and Mg²⁺-ATPase activity, and TBARS production. Our results suggest that increased ATPase activity induced by chronic ethanol consumption is due to oxidative, induced modification of membrane phospholipids and proteins, which are responsible for inhibition of ATPase activity. Increased production of TBARS induced by in vitro exposure to ethanol is not the only factor that influences ATPases activity. Further research is needed to elucidate this relationship.     

Branchial ammonia excretion in the Asian weatherloach Misgurnus anguillicaudatus

The weatherloach, Misgurnus anguillicaudatus, is a freshwater, facultative air-breathing fish that lives in streams and rice paddy fields, where it may experience drought and/or high environmental ammonia (HEA) conditions. The aim of this study was to determine what roles branchial Na⁺/K⁺-ATPase, H⁺-ATPase, and Rhcg have in ammonia tolerance and how the weatherloach copes with ammonia loading conditions. The loach's high ammonia tolerance was confirmed as was evident from its high 96 h LC₅₀ value and high tissue tolerance to ammonia. The weatherloach does not appear to make use of Na⁺/NH₄⁺-ATPase facilitated transport to excrete ammonia when exposed to HEA or to high environmental pH since no changes in activity were observed. Using immunofluorescence microscopy, distinct populations of vacuolar (V)-type H⁺-ATPase and Na⁺/K⁺-ATPase immunoreactive cells were identified in branchial epithelia, with apical and basolateral staining patterns, respectively. Rhesus C glycoprotein (Rhcg1), an ammonia transport protein, immunoreactivity was also found in a similar pattern as H⁺-ATPase. Rhcg1 (Slc42a3) mRNA expression also increased significantly during aerial exposure, although not significantly under ammonia loading conditions. The colocalization of H⁺-ATPase and Rhcg1 to the similar non-Na⁺/K⁺-ATPase immunoreactive cell type would support a role for H⁺-ATPase in ammonia excretion via Rhcg by NH₄⁺ trapping. The importance of gill boundary layer acidification in net ammonia excretion was confirmed in this fish; however, it was not associated with an increase in H⁺-ATPase expression, since tissue activity and protein levels did not increase with high environmental pH and/or HEA. However the V-ATPase inhibitor, bafilomycin, did decrease net ammonia flux whereas other ion transport inhibitors (amiloride, SITS) had no effect. H⁺-ATPase inhibition also resulted in a consequent elevation in plasma ammonia levels and a decrease in the net acid flux. In gill, aerial exposure was also associated with a significant increase in membrane fluidity (or increase in permeability) which would presumably enhance NH₃ permeation through the plasma membrane. Taken together, these results indicate the gill of the weatherloach is responsive to aerial conditions that would aid ammonia excretion.     

Resveratrol prevents oxidative stress and inhibition of Na(+)K(+)-ATPase activity induced by transient global cerebral ischemia in rats

Increased oxidative stress and energy metabolism deficit have been regarded as an important underlying cause for neuronal damage induced by cerebral ischemia/reperfusion (I/R) injury. In this study, we investigated the oxidative mechanisms underlying the neuroprotective effects of resveratrol, a potent polyphenol antioxidant found in grapes, on structural and biochemical abnormalities in rats subjected to global cerebral ischemia. Experimental model of transient global cerebral ischemia was induced in Wistar rats by the four vessel occlusion method for 10 min and followed by different periods of reperfusion. Nissl and fluoro jade C stained indicated extensive neuronal death at 7 days after I/R. These findings were preceded by a rapid increase in the generation of reactive oxygen species (ROS), nitric oxide (NO), lipid peroxidation, as well as by a decrease in Na⁺K⁺-ATPase activity and disrupted antioxidant defenses (enzymatic and non-enzymatic) in hippocampus and cortex. Administrating resveratrol 7 days prior to ischemia by intraperitoneal injections (30 mg/kg) significantly attenuated neuronal death in both studied structures, as well as decreased the generation of ROS, lipid peroxidation and NO content. Furthermore, resveratrol brought antioxidant and Na⁺K⁺-ATPase activity in cortex and hippocampus back to normal levels. These results support that resveratrol could be used as a preventive, or therapeutic, agent in global cerebral ischemia and suggest that scavenging of ROS contributes, at least in part, to resveratrol-induced neuroprotection.