Erythrocyte antioxidant enzymes in multiple sclerosis and the effect of hyperbaric oxygen

Upregulation of myeloperoxidase in patients with opticospinal multiple sclerosis: Positive correlation with disease severity

To clarify the role of myeloperoxidase (MPO) in multiple sclerosis (MS), we measured serum MPO levels in 86 Japanese patients with relapsing remitting MS, 47 with opticospinal MS (OSMS) and 39 with conventional MS (CMS), and 85 healthy subjects by sandwich enzyme immunoassays and analyzed relationships with clinical features. We found a significant increase in serum MPO in OSMS patients at relapse and remission, and in CMS patients at remission compared with controls. By logistic regression analysis, the clinical variable associated with high level of MPO at remission in OSMS patients (higher than the mean+/-2 S.D. of healthy controls) was only Kurtzke's Expanded Disability Status Scale (EDSS) score in blood sampling (p=0.0245); that is, a greater EDSS scores in the high MPO group, whereas in CMS none were associated. The results of our study suggest that MPO levels in remission are related with severe tissue destruction in OSMS.

Effect of exercise training on antioxidant system in brain regions of rat

The purpose of this investigation was to determine whether any alterations in antioxidant enzyme activities and levels of glutathione (GSH) in brain regions occurred following exercise training. Sprague-Dawley rats were given exercise training on a treadmill for 7.5 weeks and sacrificed 18 h after the last exercise along with the sedentary control rats. Different brain regions-cerebral cortex (CC), brainstem (BS), corpus striatum (CS), and hippocampus (H)-were isolated; GSH, oxidized glutathione (GSSG), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were determined. The exercise training increased SOD activity significantly (130% of sedentary control) in BS and in CS. SOD activity in H was the lowest of all four brain regions. Different brain regions showed GSH-Px activity in decreasing order for CS < BS < CC < H. GSH levels were 43% less in BS than CC and CS. The ratio of GSH/GSSG significantly increased from 6.8 to 8.3 in CC, and from 9.4 to 13.5 in BS as a result of exercise training. Different brain regions contained different activities of antioxidant enzymes, as well as GSH and GSSG levels, which were preferentially altered as a result of exercise training to cope with oxidative stress.

Increased generation of superoxide radicals in the blood of MS patients

Increased generation of superoxide radical (O2-) in the blood stimulated with phorbol myristate acetate (PMA) has been found in multiple sclerosis (MS) patients. All the subjects studied were non-smokers and received the same hospital diet. In the MS group treated with prednisone superoxide radical generation was lower than in untreated patients, but was still above the level of O2- generation in controls. Plasma lipid peroxidation products, measured as thiobarbituric-reactive substances, were slightly elevated in both prednisone treated and non-treated MS patients in comparison with controls. Erythrocyte superoxide dismutase activity (SOD) was at the same level in MS and control groups. These results suggest that increased generation of reactive oxygen species may occur in MS patients during acute relapse. This phenomenon may be involved in the pathomechanism of demyelinating disorders.

Isolation and characterization of two novel peptide amides originating from myelin basic protein in bovine brain

During a systematic search for peptides that possess the C-terminal amide structure, two novel peptide amides, one with a tyrosine amide and the other with an alanine amide were isolated from bovine brain by acid extraction and sequential steps of reversed phase HPLC. Microsequence, amino acid and mass spectral analyses revealed the structures: Ac-Ala-Ala-Gln-Lys-Arg-Pro-Ser-Gln-Arg-Ser-Lys-Tyr-amide and Ac-Ala-Ala-Gln-Lys-Arg-Pro-Ser-Gln-Arg-Ser-Lys-Tyr-Leu-Ala-Ser-Ala-amide . These 12 and 16 residues peptides had the primary structure identical to the N-terminal fragment of myelin basic protein (MBP). The peptides were therefore designated myelin peptide amide-12 (MPA-12) and -16 (MPA-16). Unlike other amidated peptides, MPA might be generated from MBP by hydroxyl radicals produced via a Fenton reaction in situ. However, this unique amidation seems to occur exclusively to MBP in a site specific manner in the brain.

Anti-oxidant capacity of spinal cord and erythrocytes of guinea pigs in case of experimental allergic encephalomyelitis and after disease suppression

In the lumbar spinal cord of EAE guinea pigs a significant increase in SOD activity, lipid hydroperoxides content (more than 60%) and Fe2(+)-ascorbate-induced lipid peroxidation was observed. Multiple injections of cytochrome C-vitamin B2-vitamin PP (CV-combination) during the disease latent period resulted in suppression of EAE development. Supplementation with vitamin C, vitamin B12 or ATP eliminated this suppressive effect. Upon treatment with CV-combination beginning on the day of the first EAE clinical signs a half of the sick animals recovered. In their erythrocytes the ratio between SOD and catalase activities was normalized, though on a higher level. In the lumbar spinal cord the concentration of lipid hydroperoxides was decreased to the control one. Oxidative damage of the central nervous system is one of the mechanisms underlying the pathogenesis of lethal EAE.

Isoprenoid biosynthesis in multiple sclerosis, II. A possible role of NADPH

Genetic predisposition in MS, influence of fat consumption on the disease, and excretion of lipid metabolites in urine led us to investigate isoprenoid metabolism in this disease. Ubiquinone concentration and biosynthesis was normal in lymphocytes. Cytochrome oxidase, which contains an isoprenoid side chain, was normal in activity. Cholesterol biosynthesis from acetate was found to be elevated in MS, and so was triglyceride biosynthesis. Increased biosynthesis may offer a very simple explanation to all the metabolites excreted (3-methylglutaconic acid, 2-hydroxy-2-methyl-3-butenoic acid and adipic acid). Increased biosynthesis may be caused by an elevated NADPH/NADP ratio, since such an elevation may also account for many other biochemical anomalies in MS. Elevated NADPH/NADP ratio may be of direct importance in the pathogenesis.

Hyperbaric oxygenation and erythrocyte antioxidant enzymes in multiple sclerosis patients

Erythrocyte glutathione peroxidase, catalase, and superoxide dismutase activities were measured in 18 patients with clinically definite MS, and results compared with those from neurological controls. These studies indicated that glutathione peroxidase activity in erythrocytes of MS patients was not different from that of the neurological controls. However, superoxide dismutase was lower in the MS patients compared to neurological controls. The effect of hyperbaric oxygenation on these erythrocyte enzymes in MS patient's was also investigated. Exposure of MS patients to 2 ata with either 10% O2 or 100% O2 had no effect on glutathione peroxidase activity. Comparison of each individual MS patient's pre- and post-treatment superoxide dismutase values indicated a significant increase after 100% O2. Similar examination of each individual's catalase activity indicated an increase after exposure to both 10% O2 and 100% O2 at 2 ata. These data suggest that erythrocyte enzyme response to oxygen stress does not involve changes in activity of all the antioxidant enzymes. Instead, only specific enzymes appear to be affected by HBO.

Lipid peroxidation products and antioxidant proteins in plasma and cerebrospinal fluid from multiple sclerosis patients

Lipid peroxidation (LPx) products were measured as thiobarbituric acid-reactive substances (TS) and lipid-soluble fluorescent pigments (FP) in both plasma and CSF from MS patients and controls. Although no significant changes were found in MS plasma, we report here for the first time increases in both TS and FP in MS CSF (p less than 0.05 and p less than 0.01, respectively, compared with patients with other neurological diseases), indicating that increased LPx in CNS may be a feature of MS. Levels of transferrin were normal but caeruloplasmin (CP), a major antioxidant plasma protein, was significantly raised in MS patients (p less than 0.01) and this may represent an adaptive response to increased oxidative challenge. Neither of these proteins was detectable in CSF using radial immunodiffusion. There was no significant correlation between the severity or duration of the disease nor the period since the last relapse and either LPx products or CP suggesting that the changes observed in this work are not simply the direct result of demyelination and tissue damage.