Zn-SOD Activity Research Articles

Carob effects on antioxidant enzyme and elements level in infertile men: Secondary data analysis from a randomized controlled trial

IntroductionAntioxidants play important roles in sperm quality. Carob (Ceratonia siliqua) is a natural source of antioxidants and it is used traditionally to improve the quality of semen. The current study aimed to evaluate the effect of carob syrup administration on the copper/zinc superoxide dismutase (Cu/Zn-SOD) activity and Zn and selenium (Se) levels in the serum of infertile men. Based on the authors knowledge, this is the first study on this topic. MethodsThis study was a parallel, randomized controlled trial that included 60 infertile men. Patients were divided randomly into two groups. Carob group received carob syrup twice a day and vitamin E group received vitamin E 100 mg twice a day for 3 months. SOD activity and Zn and Se levels were measured before and 3 months after the intervention. ResultsSe level was significantly increased in the carob and vitamin E groups after intervention; however, this difference was not significant between the two groups (P = 0.65). No significant differences were observed in SOD activity and Zn level between the carob and vitamin E groups (P = 0.07 and P = 0.65, respectively). The regression analysis showed an improvement in sperm count with increasing Se level (P = 0.05). Correlation between SOD activity and sperm motility was not significant at α = 0.05; however, it can be considered marginally significant at α = 0.1 (P = 0.08). ConclusionsCarob administration can improve Se level in infertile men; however, its effects on Zn level and SOD activity are unclear. Nevertheless, more studies are required to investigate the different doses and duration of carob administration.

CeO2 nanoparticles modulate Cu–Zn superoxide dismutase and lipoxygenase-IV isozyme activities to alleviate membrane oxidative damage to improve rapeseed salt tolerance

Rapeseed is an important cash crop. However, its yield and quality are significantly affected by salinity stress. Nanoceria helped to improve rapeseed salt tolerance via modulating Cu–Zn SOD and LOX-IV isozyme activities.

Dietary copper affects antioxidant status of shrimp (Penaeus monodon) reared in low salinity water

Graded levels of supplemental copper (Cu) (0, 10, 25, 40, 55 and 110 mg/kg) were fed to juvenile tiger shrimp (Penaeus monodon) reared in 5‰ salinity water for 8 weeks. According to the results, shrimps fed a diet supplemented with 40 mg/kg Cu had the highest weight gain (WG). Shrimps fed a diet with 110 mg/kg supplemental Cu had the lowest total haemocyte count (THC) and the highest reactive oxygen species (ROS) production and apoptotic ratio in haemocytes, suggesting that excessive levels of dietary Cu caused oxidative stress and induced haemocyte apoptosis. In plasma, the activities of copper, zinc-superoxide dismutase (Cu, Zn-SOD) and total superoxide dismutase (T-SOD) were higher in shrimps fed diets with 40 and 55 mg/kg supplemental Cu than those fed diets with ≤ 25 and 110 mg/kg supplemental Cu. Hepatic Cu, Zn-SOD activity increased in shrimps fed diets with 25–55 mg/kg supplemental Cu, while hepatic T-SOD activity increased in shrimps fed diets with 40 and 55 mg/kg supplemental Cu. In addition, diets with 25–55 mg/kg supplemental Cu increased the plasma total antioxidant capacity (T-AOC), while diets with 10–55 mg/kg supplemental Cu increased the hepatic T-AOC. Hepatic malondialdehyde (MDA) content was lowest in shrimps fed diets with 25 and 40 mg/kg supplemental Cu and highest in shrimps fed a diet with 110 mg/kg. Based on the growth and antioxidant activities, the optimum requirement of Cu for the antioxidant status of P. monodon was 30.7–61.9 mg/kg.

Sildenafil Recovers Burn-Induced Cardiomyopathy.

Background: Severe burn injury initiates a feedback cycle of inflammation, fibrosis, oxidative stress and cardiac mitochondrial damage via the PDE5A-cGMP-PKG pathway. Aim: To test if the PDE5A-cGMP-PKG pathway may contribute to burn-induced heart dysfunction. Methods: Sprague–Dawley rats were divided four groups: sham; sham/sildenafil; 24 h post burn (60% total body surface area scald burn, harvested at 24 h post burn); and 24 h post burn/sildenafil. We monitored heart function and oxidative adducts, as well as cardiac inflammatory, cardiac fibrosis and cardiac remodeling responses in vivo. Results: Sildenafil inhibited the burn-induced PDE5A mRNA level and increased the cGMP level and PKG activity, leading to the normalization of PKG down-regulated genes (IRAG, PLB, RGS2, RhoA and MYTP), a decreased ROS level (H2O2), decreased oxidatively modified adducts (malonyldialdehyde [MDA], carbonyls), attenuated fibrogenesis as well as fibrosis gene expression (ANP, BNP, COL1A2, COL3A2, αSMA and αsk-Actin), and reduced inflammation and related gene expression (RELA, IL-18 and TGF-β) after the burn. Additionally, sildenafil treatment preserved left ventricular heart function (CO, EF, SV, LVvol at systolic, LVPW at diastolic and FS) and recovered the oxidant/antioxidant balance (total antioxidant, total SOD activity and Cu,ZnSOD activity). Conclusions: The PDE5A-cGMP-PKG pathway mediates burn-induced heart dysfunction. Sildenafil treatment recovers burn-induced cardiac dysfunction.

Euterpe oleracea (Martius) Oil Reverses Testicular Alterations Caused after Cadmium Administration.

Cadmium (Cd) is an environmental pollutant that induces reproductive toxicity by generating reactive oxygen species, which leads to oxidative stress. Euterpe oleracea fruits are known for being rich in oils containing triacylglycerol and phenolic compounds. They are considered as potent antioxidants to be used to counteract Cd effects within the testis. In the present study, adult males Swiss mice were treated with CdCl2 aqueous solution (4.28mg/kg) by gavage for 7days. The experimental groups were treated with Euterpe oleracea oil at the doses of 50, 100, and 150mg/kg, for 42days. The results showed that Cd intoxication led to increased tubular pathologies, such as reduction in epithelium height and area thus increasing both luminal diameter and tubule-epithelium ratio. Besides, Leydig cell's morphometry indicated reduction in nucleus and cytoplasm volumes of this cell type, which were recovered after E. oleracea oil intake. In addition, serum testosterone levels, testicular Mn and Zn concentrations, SOD and CAT activity, and germ cell viability increased after oil intake. Therefore, E. oleracea oil showed a regenerative effect in the testicular parenchyma negatively affected by Cd, mainly in the animals that received the highest oil concentration (150mg/kg).

Superoxide dismutase: a review and a modified protocol for activities measurements in rat livers

Superoxide dismutase (SOD) enzymes are considered the first line of Defence against reactive oxygen species. Among the intracellular isoforms of SOD, Cu,ZnSOD is widely distributed, and the MnSOD is localised in the mitochondria. The SOD activities have been measured indirectly by inhibiting oxidation reactions. Most techniques assessing the hepatic SOD activity are adaptations of classical methods and differ significantly from each other. This work assessed the hepatic Cu,ZnSOD activity in the supernatants of two different centrifugations, using two isotonic medium and the pyrogallol method. In most studies conducted in rat liver, only the Cu,Zn or total SOD activities were assessed and sometimes the Cu,ZnSOD activity was calculated based on the inhibition by cyanide. But, as demonstrated here, this inhibition is not complete. Besides, the novelty of this work is that we presented a method for the evaluating the Cu,ZnSOD and MnSOD activities separately and from the same liver.

The Analysis of Cu(II)/Zn(II) Cyclopeptide System as Potential Cu,ZnSOD Mimic Center

In this paper are presented the features of copper (II) and zinc (II) heteronuclear complexes of the cyclic peptide—c(HKHGPG)2. The coordination properties of ligand were studied by potentiometric, UV–Vis and CD spectroscopic methods. These experiments were carried out in aqueous solutions at 298 K depending on pH. It turned out that in a physiological pH dominates Cu(II)/Zn(II) complex ([CuZnL]4+) which could mimic the active center of superoxide dismutase (Cu,ZnSOD). In next step we performed in vitro research on Cu,ZnSOD activity for [CuZnL]4+ complex existing in 7.4 pH by the method of reduction of nitroblue tetrazolium (NBT). Also mono- and di-nuclear copper (II) complexes of this ligand were examined. The ability of inhibition free radical reaction were compared for all complexes. The results of these studies show that Cu(II) mono-, di-nuclear and Cu(II)/Zn(II) complexes becoming to new promising synthetic superoxide dismutase mimetics, and should be considered for further biological assays.

Crucial Roles of Systemic and Tissue Lipid Peroxidation Levels and Anti-Oxidant Defences Following Contrast Agent Application.

BackgroundOne of the most important side effects of contrast pharmaceutical agents, which are used very common in routine radiology practice, is contrast induced nephropathy. Even ischemia, oxidative stress and osmolality related cytotoxic effects are considered, the molecular mechanisms underlying this pathology have not been identified completely yet.ObjectivesThe aim of the current study was to reveal the role of oxidative stress and antioxidant enzymatic defence mechanisms in the aetiopathogenesis of contrast-induced nephropathy. We also studied possible alleviating effects of N-acetylcysteine (NAC), a potent antioxidant, to obtain extra information regarding the molecular mechanisms underlying this pathology.Materials and MethodsThis is an clinical-experimental study, This study was conducted of Istanbul/Turkey between September 15, 2012 and April 15, 2013. Three groups of male rats were randomly set up as a control group (C), a 100 mg/kg intraperitoneal NAC + 7 mL/kg contrast agent group (N + CIN) and a 7 mL/kg intraperitoneal contrast agent group (CIN). They were placed in individual metabolic cages 48 hours after agent administration to obtain 24-hour urine samples. Renal function tests (albumin, urea, creatinine, total protein) were conducted, oxidative stress parameters (Cu, Zn superoxide dismutase activity - Cu, Zn-SOD; advanced oxidation protein products - AOPP; protein carbonyls - PCO; total thiol groups - T-SH; and lipid hydroperoxides -LHP) were measured and tissues were analysed histopathologically.ResultsCompared with the control group, groups CIN and N + CIN had significantly higher urea and LHP levels (P < 0.05 and P < 0.001, respectively) and significantly lower Cu, Zn-SOD activity and creatinine clearance (P < 0.05). There was no statistically significant difference between the groups in PCO or AOPP levels despite differences in descriptive statistics.ConclusionsContrast-agent-induced nephropathic changes are more closely related to the magnitude of lipid peroxidation than protein oxidation.

Dietary copper requirement of juvenile Russian sturgeon Acipenser gueldenstaedtii

To quantify the dietary copper (Cu) requirement of Russian sturgeon Acipenser gueldenstaedtii, copper sulfate (CuSO4·5H2O) was added into the basal semi-purified diet at seven levels 0, 1, 2, 4, 6, 8 and 16mgCukg−1 diet yielding the actual dietary values of 0.3, 1.5, 2.4, 4.4, 6.2, 8.3 and 16.1mgCukg−1 diet, respectively. Each diet was fed to sturgeon (11.84±0.07g) in triplicate in a flow-through system for 8weeks. The Cu concentration in the rearing water was 0.8–1.2μgL−1 during the trial period. The weight gain rate (WGR) and feed efficiency were significantly higher in fish fed 2.4 to 8.3mgCukg−1 than those fed 0.3, 1.5 or 16.1mgCukg−1. The highest WGR was found in fish fed 6.2mgCukg−1. The whole-body Cu concentrations were highest in fish fed 6.2 to 16.1mgCukg−1. The liver Cu concentration was highest in fish fed 16.1mgCukg−1 diet and lowest in fish fed diets Cu levels range from 0.3 to 4.4mgCukg−1. Hepatic copper–zinc superoxide dismutase (Cu–Zn SOD) activities, total antioxidant capacity and serum ceruloplasmin activity were significantly higher in fish fed 6.2 and 8.3mgCukg−1 diet than those in other treatments. The lowest hepatic malondialdehyde values were observed in fish fed 6.2 and 8.3mgCukg−1. No significant differences were in survival, hepatosomatic index, viscerosomatic index and condition factor among all the treatments. There were also no significant differences in whole body moisture, crude protein, crude lipid and ash between all the treatments. Analysis of broken-line regression based on the WGR, whole-body Cu concentration, hepatic Cu–Zn SOD and serum ceruloplasmin activity of the fish fed different diets indicates that the minimum Cu concentration in the semi-purified diet for juvenile Russian sturgeon (12–70g) is at 7–8mgkg−1. Statement of relevanceThe dietary copper (Cu) requirement of juvenile Russian sturgeon was investigated. Dietary Cu deficiency and over-loading significantly reduced growth, feed utilization and antioxidant capacity. The results suggest that the appropriate dietary Cu content is considerable in Russian sturgeon farming. Minimum dietary Cu level for this species is recommend as 7–8mgCukg−1 in this study. These information will be useful in developing a practical diet for Russian sturgeon culture.

Apelin-12 and its structural analog enhance antioxidant defense in experimental myocardial ischemia and reperfusion.

This study investigated the effects of peptide apelin-12 (H-Arg-Pro-Arg-Leu-Ser-His-Lys-Gly-Pro-Met-Pro-Phe-OH, A12) and its novel structural analog (H-(NαMe)Arg-Pro-Arg-Leu-Ser-His-Lys-Gly-Pro-Nle-Pro-Phe-OH, AI) on myocardial antioxidant enzyme activities, lipid peroxidation, and reactive oxygen species formation in ex vivo and in vivo models of myocardial ischemia/reperfusion (I/R) injury. Isolated working rat hearts were subjected to global ischemia and reperfusion. Infusion of 140 μM A12 or AI before global ischemia improved cardiac function recovery; increased the activity of Cu,Zn superoxide dismutase (Cu,Zn SOD), catalase (CAT), and glutathione peroxidase (GSH-Px); decreased malondialdehyde (MDA) content in reperfused heart; and reduced the formation of hydroxyl radical adduct of the spin trap 5,5-dimethyl-1-pyrroline-N-oxide in the myocardial effluent during early reperfusion compared with these indices in control. Anesthetized open-chest rats were subjected to the left anterior descending coronary artery occlusion and coronary reperfusion. Peptide A12 or its analog AI was injected intravenously at the onset of reperfusion at a dose of 0.35 μmol/kg. Treatment with A12 or AI significantly limited infarct size and reduced the activity of lactate dehydrogenase and creatine kinase MB isoenzyme in blood plasma at the end of reperfusion compared with control. These effects were accompanied by complete recovery of Cu,Zn SOD, CAT, and GSH-Px activities; and decrease in MDA content in the area at risk by the end of reperfusion. The study concluded that C-terminal fragment of native peptide apelin-12 and its synthesized analog is involved in the upregulation of cardiac antioxidant defense systems and attenuation of lipid peroxidation in myocardial I/R injury.

Maturation increases superoxide radical production without increasing oxidative damage in the skeletal muscle of hooded seals (Cystophora cristata)

Diving vertebrates represent unique models for the study of the physiological responses to reactive oxygen species (ROS) production and oxidative stress because of their adaptability to cope with dive-derived ROS production. We hypothesized that in the skeletal muscle of a diving mammal, the hooded seal ( Cystophora cristata (Erxleben, 1777)), ROS production increases with maturation but the accumulation of oxidative damage does not. To test this, we analyzed the tissue capacity to produce ROS, the accumulation of oxidative damage, and the activity and protein content of the cooper, zinc, and manganese dependent superoxide dismutases (Cu,ZnSOD, MnSOD) in skeletal muscle from neonates, weaned pups, and adult hooded seals. Our results showed higher tissue capacity to produce ROS, higher Cu,ZnSOD and MnSOD activities, and higher MnSOD protein content in adult seals than in pups. No differences in oxidative damage to lipids, proteins, or DNA were detected among groups. Results suggest that increased SOD activity likely counters the oxidative damage commonly associated with increased ROS production. These findings highlight the unusual tolerance of skeletal muscle of seals to increased ROS production.

ROS formation and antioxidant status in brain areas of rats exposed to sodium metavanadate

In the present work, in vivo ROS formation and the activity of antioxidant enzymes in the hippocampus and the cerebellum of sodium metavanadate (NaVO 3) treated rats were studied. Rats were i.p. injected with 3 mg/kg bw/day ( V 1 group) or with 7.2 mg/kg bw/day of NaVO 3 ( V 2 group) for 5 consecutive days. Results show that after only 5 days of NaVO 3 exposure, reactive oxygen species formation and alteration of the oxidative defence system were observed. Vanadium-induced OH production was detected in cerebellum at the high dose. This result was confirmed by in situ ROS histochemical staining. Neither Cat nor Cu–Zn SOD activities showed changes while GSH/GSSG ratio, in both brain areas, was significantly decreased in NaVO 3-treated groups. The present work indicates that the NaVO 3 dose and the particular brain area constitution would be critical in the cellular and molecular oxidative mechanism of this element.

Dietary copper requirement reevaluation for juvenile grouper, Epinephelus malabaricus, with an organic copper source

To reevaluate the dietary copper (Cu) requirements of grouper, Epinephelus malabaricus, with an organic Cu source, Cu peptide was added to a basal diet at 0, 1, 2, 3, 4, 8 and 12 mg Cu/kg, providing actual dietary values of 0.19, 1.81, 2.55, 3.43, 4.37, 8.99 and 12.81 mg Cu/kg for a total of 7 experimental diets. Each diet was fed to triplicate groups of fish (initial body weight: 21.60 ± 0.08 g) in a recirculating seawater rearing system for 8 wks. Weight gain (WG) was highest ( P < 0.05) in fish fed the diet with 2.55 mg Cu/kg, followed by fish fed the diet with 3.43 mg Cu/kg, and lowest in fish fed diets with 0.19, 8.99 and 12.81 mg Cu/kg. Hepatic copper–zinc superoxide dismutase (Cu–Zn SOD) activity was highest in fish fed the diet with 2.55 mg Cu/kg, followed by fish fed diets with 3.43, 8.99, 1.81 and 12.81 mg Cu/kg (in order of decreasing activity), and lowest in fish fed the diet with 0.19 mg Cu/kg. Hepatic thiobarbituric acid-reactive substance (TBARS) value was lowest in fish fed diets with 2.55 and 3.43 mg Cu/kg, followed by fish fed diets with 0.19 and 4.37 mg Cu/kg, and highest in fish fed the diet with 12.81 mg Cu/kg. Analysis by broken-line regression of WG, hepatic Cu–Zn SOD activity and TBARS value, and by linear regression of whole-body Cu retention of the fish indicated that the adequate dietary Cu requirement for grouper determined by Cu-peptide is about 2–3 mg Cu/kg.

Antioxidants activities and concentration of selenium, zinc and copper in preterm and IUGR human placentas

The aim of this study was to examine changes in activities of cytochrome c oxidase (CCO), glucose-6-phosphate dehydrogenase (G6PDH), Cu–Zn superoxide dismutase (Cu–Zn SOD), glutathione peroxidase (GSH-Px), glutathione (GSH) levels and copper (Cu), zinc (Zn) and selenium (Se) concentrations, and to assess the possible differences between preterm placentas, placentas from term pregnancies complicated by intrauterine growth restriction (IUGR) and full-term control placentas. The enzyme activities and the level of GSH decreased in IUGR and preterm placentas in comparison with the control group. CCO activity and GSH level in preterm placentas were markedly lower compared with the IUGR ( P<0.01; P<0.05) and control ( P<0.01; P<0.05) placentas, respectively. In IUGR placentas the level of Cu was reduced by 23% ( P<0.05) and Zn by 37%. In preterm placentas the level of Cu was reduced by 19% and Zn by 42%. Se level in IUGR and preterm placentas was higher ( P<0.05) by 28% and 32% than in control group, respectively. The strong relation was observed between birth weight and CCO activity, birth weight and Cu–Zn SOD activity, and a low level of Zn and Cu influenced the birth weight especially in IUGR cases. Moreover, the strong inverse correlation between Se level and birth weight, Se level and placental weight and Se level and CCO activity are new findings.

Superoxide dismutase of plant cell vacuoles

Metal-dependent superoxide dismutases (SOD; EC 1.15.1.1) are present in many cell compartments (mitochondria, plastids, nuclei, peroxisomes, endoplasmic reticulum, cell wall and cytosol). We have established that SOD is also localized in the central vacuole. Cyanide-sensitive Cu, Zn-SOD was found in the fraction of isolated vacuoles of red beet roots (Beta vulgaris L.). The enzyme was represented by three isoforms. Comparison of isoenzyme composition and the level of SOD activity in vacuoles, nuclei, plastids and mitochondria isolated from root cells has shown that Cu, Zn-SOD is present in vacuoles and nuclei, two SOD forms (Cu, Zn- and Fe-SOD) are present in plastids, and two SOD forms (Cu, Zn- and Mn-SOD) are present in mitochondria. Cu, Zn-SOD of organelles, unlike vacuolar Cu, Zn-SOD, had only one isoform. The level of enzyme activity from the vacuolar fraction was twice higher than the level of SOD activity from the fractions of isolated organelles. Previously it has been suggested that Cu, Zn-SOD may be localized on the vacuolar membrane or in the near-membrane space from the side of cytoplasm. Our tests have revealed the Cu, Zn-SOD activity in water-soluble extracts of isolated vacuole fractions in the absence of detergent, which may confirm localization of the enzyme inside the organelles.

Superoxide dismutase activity as a measure of hepatic oxidative stress in cattle following ethionine administration

The goal of this study was to assess if oxidative stress, as measured by alterations in the concentrations of antioxidant enzymes in the liver and erythrocytes of cattle, could be induced following dl-ethionine administration. Whole blood, serum and liver biopsy samples were collected 0, 4, 7 and 10 days after intra-peritoneal ethionine administration to five cows. The activities of the antioxidant enzymes copper zinc superoxide dismutase (Cu, Zn SOD) and catalase were assessed in the liver biopsies which were also examined histopathologically. Significant increases in hepatic Cu, Zn SOD concentrations (P<0.01) were noted on days 7 and 10 post-treatment. Hepatic catalase activity decreased significantly (P<0.01) on days 4, 7 and 10 post-treatment and erythrocyte Cu, Zn SOD activity was significantly increased on day 10. Serum biochemical analysis revealed a significant increase (P<0.01) in non-esterified fatty acid concentrations on day 4 and significant decreases in total cholesterol and phospholipid levels on days 4 (P<0.05), 7 (P<0.01) and 10 (P<0.01). In this model system, dl-ethionine administration was effective in inducing oxidative stress particularly reflected in the liver.

Association between enzymatic and non-enzymatic antioxidant defense mechanism with apolipoprotein E genotypes in Alzheimer disease

Objective There are evidence suggesting that APOE-ɛ4 allele play an important role in the pathogenesis of Alzheimer's disease (AD) by reducing peripheral levels and activities of a broad spectrum of nonenzymatic and enzymatic antioxidants systems. However, the link between APOE genotype, oxidative stress, and AD has yet to be established. In this study we examined whether antioxidant defense mechanism exacerbates the risk of AD in individual carrying APOE-ɛ4 allele in a population from Tehran, Iran. Method We determined the enzymatic activities of the erythrocyte Cu–Zn superoxide dismutase (Cu–Zn SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and serum level of total antioxidant status(TAS) in various APOE genotypes in 91 patients with AD and 91 healthy subjects as control group (age and sex-matched). Result The results showed that the TAS level and the activities of enzymatic antioxidants CAT and GSH-Px were significantly lower and the SOD activity was significantly higher in AD patients compared to controls. The AD patients with APOE-ɛ4 allele genotype had significantly lower serum TAS concentration and lower erythrocytes GSH-Px and CAT activities ( p = 0.001) but significantly higher erythrocytes Cu–Zn SOD activity ( p = 0.001) than the non-APOE-ɛ4 carrier AD and the control group. In addition, the association observed between the factors involved in an antioxidant defense mechanism and APOE-ɛ4 allele in AD increased with age of the subjects. Conclusion These data indicate that the reduced serum level of TAS and activity of CAT, GSH-Px and increased SOD exacerbate the risk of AD in individuals carrying APOE-ɛ4 allele. The reduced antioxidants defense in APOE–ɛ4 allele carrier may contribute to beta-amyloidosis. This effect, however, is more pronounced in the AD patients older than 75 years of age. This suggests that a therapeutic modality should be considered for these subjects.

Biochemical Characterization of G93A Mutant human Cu, Zn Superoxide Dismutase Purified from Transgenic Rat Spinal cord

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with no cure and mutations to Cu‐Zn superoxide dismutase (SOD1) remain the only proven cause of the disease. SOD1, a 32‐kDa homodimer, is a ubiquitously expressed cytosolic antioxidant enzyme with one Cu and one Zn per monomer stabilized by an intra‐subunit disulfide (Cys 57 and Cys 146) bond. It also contains two more cysteines (Cys 6 and Cys 111) thought to be present as reduced thiols. To identify the potential mechanisms by which the mutant SOD1 (mSOD1) mediates neurotoxicity, we purified the mSOD1 from pre‐symptomatic and end stage ALS‐associated G93A mutant rat spinal cords (a model for ALS) using simple reverse‐phase preparative HPLC. The purified mSOD1 was characterized in terms of Cu and Zn levels, SOD activity, and thiol content using chromophoric chelation assay, SOD activity assay and thiol assay respectively. Our results indicate that Zn levels were significantly higher in mSOD1 purified from end stage cord to that of pre‐symptomatic cord, however no significant differences were observed in Cu levels and specific activities. Interestingly, thiol assay revealed that Cys 111 exists primarily in an oxidized state with Cys 6 primarily in the reduced state. These results suggest that biochemical impact of altered Zn affinity and cysteine modifications on SOD1 could have important implications in disease progression.

Hyperlipidemia induced by a cholesterol-rich diet aggravates necrotizing pancreatitis in rats

The aim of the present study was to investigate whether hyperlipidemia can cause acute pancreatitis or alter its severity. Male Wistar rats were fed a 3% cholesterol-enriched diet or a normal diet for 16 weeks. Edematous and necrotizing pancreatitis was induced with 3x75 mug/kg body weight of cholecystokinin s.c. and 2x2 g/kg body weight of L-arginine i.p., respectively, in separate groups of normal and hyperlipidemic rats. The severity of the pancreatitis was assessed. We studied the influence of hyperlipidemia on the formation of oxygen-derived free radicals, endogenous scavengers, nitric oxide synthases (NOS), peroxynitrite (ONOO(-)), heat shock protein 72 (HSP72) and nuclear factor-kappa B (NF-kappaB) activation in the pancreas during acute edematous and necrotizing pancreatitis. Hyperlipidemia did not worsen edematous, but aggravated necrotizing pancreatitis. The cholesterol-enriched diet significantly reduced the catalase and Mn-superoxide dismutase (SOD) and constitutive NOS (cNOS) activities and increased the inducible NOS (iNOS) in the pancreas relative to those in the rats on the normal diet. The pancreatic nitrotyrosine level, as a marker of ONOO(-), and the NF-kappaB DNA-binding activity in the pancreas, were significantly elevated in the cholesterol-fed rats. The pancreatic HSP72 expression during necrotizing pancreatitis was not influenced by the hyperlipidemia. The pancreatic Mn-SOD, Cu, Zn-SOD, glutathione peroxidase, total glutathione and cNOS activities were significantly reduced, while the catalase, iNOS and NF-kappaB DNA-binding activities were significantly increased in the animals with necrotizing pancreatitis on the cholesterol diet as compared with those with pancreatitis and receiving the normal diet. Hyperlipidemia induced with this cholesterol-enriched diet leads to decreases in endogenous scavenger and cNOS activities, results in iNOS and NF-kappaB activation and stimulates ONOO(-) generation in the pancreas, which may be responsible for the aggravation of acute necrotizing pancreatitis.

The effect of sulfur dioxide inhalation on active avoidance learning, antioxidant status and lipid peroxidation during aging

The effect of SO 2 was examined on active avoidance learning, thiobarbituric acid reactive substances (TBARS), and the activities of Cu, Zn superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in young (3 months), middle-age (12 months ), and old (24 months) Swiss male albino rats. Ten ppm SO 2 was administered to the animals of SO 2 groups in an exposure chamber for 1 h/day × 7 days/week × 6 weeks while control groups were exposed to filtered air in the same condition. The most prominent effect of aging on active performance was also observed in the older group. SO 2 exposure significantly decreased the active avoidance learning in the young group, but it had no effect on this parameter in the middle-aged and the older group compared with their corresponding control groups. SO 2 exposure resulted in increased levels of Cu, Zn-SOD activity while decreased level of GSH-Px activity in all experimental groups compared with their corresponding control groups. CAT activities were unaltered. TBARS levels of all SO 2 exposed groups were significantly increased compared with their respective control groups. In conclusion, results from the present research showed that SO 2 exposure resulted in an increase in the lipid peroxidation and caused alterations in antioxidant enzyme activities. Additionally, SO 2 exposure impaired cognitive function only in the young rats during the acquisition phase of active avoidance learning.