Multifaceted superoxide dismutase 1 expression in amyotrophic lateral sclerosis patients:a rare occurrence?

Amyotrophic lateral sclerosis(ALS)is a neuromuscular condition resulting from the progressive degeneration of motor neurons in the cortex,brainstem,and spinal cord.While the typical clinical phenotype of ALS involves both upper and lower motor neurons,human and animal studies over the years have highlighted the potential spread to other motor and non-motor regions,expanding the phenotype of ALS.Although superoxide dismutase 1(SOD1)mutations represent a minority of ALS cases,the SOD1 gene remains a milestone in ALS research as it represents the first genetic target for personalized therapies.Despite numerous single case reports or case series exhibiting extramotor symptoms in patients with ALS mutations in SOD1(SOD1-ALS),no studies have comprehensively explored the full spectrum of extramotor neurological manifestations in this subpopulation.In this narrative review,we analyze and discuss the available literature on extrapyramidal and non-motor features during SOD1-ALS.The multifaceted expression of SOD1 could deepen our understanding of the pathogenic mechanisms,pointing towards a multidisciplinary approach for affected patients in light of new therapeutic strategies for SOD1-ALS.

Research Progress on Synthesis of Superoxide Dismutase Mimics

Research on the synthesis of superoxide dismutase mimics by chemical and biologi-cal synthetic methods were reviewed.The advantages and limitations were analyzed.A prospect for the future development of superoxide dismutase mimics is proposed.

The landscape of cognitive impairment in superoxide dismutase 1-amyotrophic lateral sclerosis

Although mutations in the superoxide dismutase 1 gene account for only a minority of total amyotrophic lateral sclerosis cases,the discovery of this gene has been crucial for amyotrophic lateral sclerosis research.Since the identification of superoxide dismutase 1 in 1993,the field of amyotrophic lateral sclerosis genetics has considerably widened,improving our understanding of the diverse pathogenic basis of amyotrophic lateral sclerosis.In this review,we focus on cognitive impairment in superoxide dismutase 1-amyotrophic lateral sclerosis patients.Literature has mostly reported that cognition remains intact in superoxide dismutase 1-amyotrophic lateral sclerosis patients,but recent reports highlight frontal lobe function frailty in patients carrying different superoxide dismutase 1-amyotrophic lateral sclerosis mutations.We thoroughly reviewed all the various mutations reported in the literature to contribute to a comprehensive database of superoxide dismutase 1-amyotrophic lateral sclerosis genotype-phenotype correlation.Such a resource could ultimately improve our mechanistic understanding of amyotrophic lateral sclerosis,enabling a more robust assessment of how the amyotrophic lateral sclerosis phenotype responds to different variants across genes,which is important for the therapeutic strategy targeting genetic mutations.Cognition in superoxide dismutase 1-amyotrophic lateral sclerosis deserves further longitudinal research since this peculiar frailty in patients with similar mutations can be conditioned by external factors,including environment and other unidentified agents including modifier genes.

牛血超氧化物歧化酶(bovine superoxide dismutase)生产工艺研究

将红细胞连续分离、热变性以及超滤技术应用在牛血 SOD生产制备中 ,使 SOD生产成本大幅降低 ,实现牛血 SOD生产工业化 .实验表明 ,冷冻血球和新鲜血球在酶的收率、纯度以及比活等方面无明显差别 ;热变性、超滤、丙酮沉淀等各工艺步骤酶的活性以及收率基本稳定 ;通过重组 SOD技术使失去铜锌离子失活的酶蛋白恢复酶的催化活性 .

Purification and Properties of Superoxide Dismutase(SOD) in Allium Sativum

Superoxide dismutases(SODs) were purified to homogeneity from Allium Sativum by means of ammonium sulfate precipitation and column chromatography with DEAE-cellulose(DE52) and Sephadex G-75. Based on sodium dodecyl sulfate\|polyacrylamide gel electrophoresis(SDS-AGE), Allium Sativum is predicted to contain four SODs. The molecular weights of the native SODs are 41 3 kD, 37 0 kD, 35 2 kD and 31 0 kD, which consist of subunits of 20 7 kD, 18 4 kD, 17 7 kD and 15 4 kD respectively. Because of their specific sensitivity to hydrogen peroxide, cyanogens potassium and chloroform\|alcohol, the SODs in Allium Sativum appear to be Cu, Zn-SOD isoenzymes. The isoelectric analysis indicates that three of the four isoenzymes are acidic proteins with isoelectric points at pH 3 5, 3 7 and 4 0, respectively, and the fourth one is a basic protein with isoeletric point at pH 8 5.

Differential Expression of Two Cytosolic Ascorbate Peroxidases and Two Superoxide Dismutase Genes in Response to Abiotic Stress in Rice

Superoxide dismutase (SOD) and ascorbate peroxidase (APX) play central roles in the pathway for scavenging reactive oxygen species in plants, thereby contributing to the tolerance against abiotic stress. Here we report the responses of cytosolic SOD (cSOD; sodCc1 and sodCc2) and cytosolic APX (cAPX; OsAPX1 and OsAPX2) genes to oxidative and abiotic stress in rice. RNA blot analyses revealed that methyl viologen treatment caused a more prominent induction of cAPXs compared with cSODs, and hydrogen peroxide treatment induced the expression of cAPXs whereas cSODs were not affected. These results suggest that cAPXs play more important roles in defense against oxidative stress compared with cSODs. It is noted that cSODs and cAPXs showed coordinate response to abscisic acid treatment which induced both sodCc1 and OsAPX2. However, cSODs and cAPXs responded differentially to drought, salt and chilling stress, which indicates that cSOD and cAPX genes are expressed differentially in response to oxidative and abiotic stress in rice.

Expression and Characterization of an Active Chimeric Protein of Human Extracellular Superoxide Dismutase and hCuZnSOD in Pichia pastoris

Mammalian cells express two isoforms of Cu- and Zn-containing superoxide dismutases（SODs）, CuZn-SOD and extracellular SOD（EC-SOD）, involved in the defense system against reactive oxygen species（ROS）. The two SODs have structurally homologous centre domain with distinct N- and C-terminuses, resulting in the different characteristics of the structure and function of the two molecules. We generated a hybrid SOD molecule（namely hy- SOD） via replacing the N- and C-terminuses of hCuZnSOD with the counterparts of hEC-SOD. The hySOD was expressed in host Pichia pastoris and the purified protein was a dimer with a molecular weight of about 34000. A series of activity analyses indicates that the hySOD is similar to hEC-SOD in heat-stability, and has the activity of protecting the host cell against heat shock and oxidative stress. Our results show evidence for the study on the compound activity of multiple SOD molecules, and may be important for understanding the relationship between structure and function of hEC-SOD and hCuZnSOD.

Relationship of Uric Acid with Superoxide Dismutase (Sod) in Induced Hyperuricemic Rat Model

Increase uric acid levels have been found in oxidative stress. Urate radicals do not react with oxygen to form another peroxy radical, thus increasing the efficacy of uric acid as an antioxidant. Therefore, this study is designed to measure the level of uric acids and find out the relationship of uric acid with superoxide dismutase in induced hyperuricemic model. Forty male albino rats with an average weight of 180 ± 2 g were selected. The rats were grouped. The animals were fed on standard diet and given tap water ad libitum until treatment. Albino rats were divided into four groups. Group A(10)-control given only standard diet, group B(10) fed on 60% fructose with standard diet , group C(10) fed on fructose, standard diet and intraperitonially oxonic acid 250 mg/kg and group D (10) only on injection intraperotonially oxonic acid 250 mg/kg. At the end of study 10 mL of blood was drawn from heart of rats. Then blood was estimated for superoxide dismutase and uric acids done by kit methods randox-manual/Rx monza UA230/UA 233. Results: In Group C superoxide dismutase was found to be 32 % (244 mg/dL ± 2.23) more than control. In the same group the uric acid concentration was highly significantly correlated with control. Conclusion: The uric acid concentration increases when we take fructose up to 60% in our diet. It also increases superoxide dismutase concentration. More than this value may have inverse effect on the uric acid level and its role as an antioxidant may become inversed.

Characterization of a thermostable manganese-containing superoxide dismutase from inshore hot spring thermophile Thermus sp.JM1

A thermostable superoxide dismutase （SOD） from the inshore thermophile Thermus sp. JM1 was purified to homogeneity by steps of fractional ammonium sulfate precipitation, DEAE-Sepharose chromatography and Phenyl-Sepharose chromatography. The specific activity of the purified native enzyme was 1 656 U/mg. A sod gene from this strain was cloned and overexpressed in Escherichia coli （E. coli）. The prepared apo-enzyme of the purified recombinant SOD （rSOD） was reconstituted with either Fe or Mn by means of incubation with appropriate metal salts. As a result, only Mn 2＋ - reconstituted rSOD （Mn-rSOD） exhibited the specific activity of 1 598 U/mg. SOD from Thermus sp. JM1 was Mn-SOD, judging by the specific activities analysis of Fe or Mn reconstituted rSODs and the insensitivity of the native SOD to both cyanide and H 2 O 2 . Both the native SOD and Mn- rSOD were determined to be homotetramers with monomeric molecular mass of 26 kDa and 27.5 kDa, respectively. They had high thermostability at 50 ° C and 60 ° C, and showed striking stability across a wide pH span from 4.0 to 11.0.

Purification and Characterization of Superoxide Dismutase(SOD) from Camellia Pollen

A superoxide dismutase（ SOD ） was purified to homogeneity from fresh camellia pollen by means of ammonium sulfate precipitation and column chromatography with DEAE-cellulose（ DE52 ）, Sephadex G-100 and phenyl sepharose^TM 6 Fast Flow columns. Its specific activity could reach to 4034 U/mg protein and it was determined to be Cu/ Zn-SOD according to its different sensitivities to different inhibitors. The molecular weight of the SOD and its subunit were 69500 and 34700, respectively, based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS- PAGE）, which implicates that the SOD in camellia pollen is a dimmer composed of two identical subunits. The isoelectric point of the enzyme was determined to be 4. 1 by isoelectric focusing electrophoresis and the N-terminal amino acid was identified to be Gly by the DNS-Cl method. Its α-Helix was also calculated to be approximately 21.8% according to the circular dichroism（CD） spectra.

A Novel Isoenzyme of CuZn-superoxide Dismutase from Nicotiana tobacum

An isoenzyme of CuZnsuperoxide dismutase, denoted as CuZnSODⅢ, has been separated and purified from Nicotiana Tobacum (tobacco) leaves to apparent homogeneity. Its molecular mass is 22976.6Da. It is composed of one subunit, which is consisted of 187 amine acid residues and contains 1 copper and 0.5 zinc atom. The activation energy of the thermal denaturation process has been obtained as about 143.5kJmol-1. Meanwhile, some properties of spectra were investigated.

Regulation of Content of Malondialdehyde by Siqi Decoction via Increasing Activity of Superoxide Dismutase in Blood Serum of Rats with Myocardial Ischemia

Effect of Siqi decoction on myocardial ischemia is to prevent cardiac myocyte membrane from damage associated with oxygen free radicals related to NO. To research the regulatoin of the content of malondialdehyde by Siqi decoction, an index of lipid peroxidation, via increasing activity of superoxide dismutase in blood serum of rats with Myocardial Ischemia, the model of myocardium ischemia was made in Wistar rats with posterior pituitary injection through vein in tail. Siqi decoction, Diaoxinxuekang（DK） and Fufangdanshenpian（FD）, the latter two drugs of which are effective TCM drugs of anti-myocardial ischemia at present, were administrated to the rats with myocardium ischemia for 5 days to compare the effect of them on myocardium ischemia as reference drugs via measuring the changes of the content of malondialdehyde and the activity of superoxide dismutase in the rat blood serum with myocardial ischemia. There were a remarkable increase in the activity of superoxide dismutase and a decrease in the content of malondialdehyde in the serum of the rats administered Siqi decoction compared with those of the rats in control group, p〈0.05. The contents of MDA in the serum of the prevention group rats in the experiments are lower than those of the cure group rats. Anti-Myocardium Ischemia mechanism of Siqi decoction is the regulation of the content of malondialdehyde via increasing activity of superoxide dismutase in the serum of Rats with myocardial ischemia and stimulating the activity of NOS in serum so as to increase NO concentration.

Glutathione peroxidase, superoxide dismutase and catalase activities in children with chronic hepatitis

The advantages of measuring hepatic oxidative status in liver biopsy are that it helps in diagnosis of hepatic dysfunction, reflects the degree of deterioration in the liver tissues, and helps to determine the severity of hepatic injury. We aimed to study the oxidative stress state in children with chronic hepatitis by using indirect approach in which antioxidant enzymes such as glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT) are determined in the liver tissue. The present study included 21 children and adolescents (12 males, 9 females) suffering from chronic hepatitis. Patients were selected from the Hepatology Clinic, New Children’s Hospital, Cairo University from November 2006 till 2009 and compared with a group of 7 children who happened to have incidental normal liver biopsy. Children with chronic hepatitis had mean age 8.12 ± 1.15 years. It was further subdivided into 2 subgroups: chronic viral heaptitis (n = 13) and cryptogenic hepatitis (n = 8). GPX, SOD and CAT levels were measured in fresh liver tissue (cell free homogenates) using ELISA. In chronic hepatitis group;there was a significant increase in the hepatic GPX activity (38.59 ± 35.82 nmol/min/ml) as compared to the control group (10.62 ± 6.68 nmol/min/ml). Also a significant correlation was observed between SOD and both ALT (r = 0.87, p < 0.05) and AST (r = 0.74, p < 0.05). GPX correlated with ALT (r = 0.80, p < 0.05) level in the chronic viral hepatitis subgroup. Our findings suggest that oxidative stress could play a role in the pathogenesis of chronic hepatitis. These preliminary results are encouraging to conduct more extensive clinical studies combining antioxidant therapy with various treatments.

αB-crystallin malondialdehyde,superoxide dismutase, and lutathione peroxidase changes in X-ray irradiated rat lens

AIM: To evaluate αB-crystallin malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPx) changes in X-ray irradiated rat lens. METHODS: Eight-week-old Sprague-Dawley male rats received X-ray irradiation to the head with rest of the body protected. The exposure dose ranged from 2 to 25 Grays (Gy). The cataract status were examined by slit lamp and rated with 'four-grade systems' post-irradiation. The lens MDA level, and the activities of SOD and GPx were measured in a short-term experiment post-irradiation, and αB-crystallin protein levels were quantified. RESULTS: The lenses of normal control and the X-ray irradiated groups with the dose up to 10 Gy remained transparent throughout the experiment. The lens first appeared tiny scatters, and even lamellar opacities in the posterior capsule 45 days post-irradiation with the dose of 15 Gy, and progressed slowly to the advance stage of cataract; while, for the higher dose (25 Gy), the opacity of lens appeared much earlier, and progressed more rapidly to mature stage of cataract within 1 month. At the end of the observation (90 days post-irradiation), almost all lenses became complete opacity with the higher dose (25 Gy). The degree of lens opacity was rated accordingly. The lens MDA level was increased, and SOD and GPx activities were decreased with a dose-dependent manner post-irradiation. The αB-crystallin protein level was decreased dose-dependently at the end point of observation. CONCLUSION: Oxidative events and αB-crystallin may play important roles in the pathogenesis of cataract in X-ray irradiated rat lens.

INFLUENCE OF ZINC，MANGANESE AND SELENIUM ONSUPEROXIDE DISMUTASE ACTIVITY IN LUNGCANCER TISSUE AND CELL IN CULTURE

In this experiment,the cancer tissues and cells,Which were derived from Lewis lung cancer and A549 lung Cancer cell line,were respectively divided into four groups and zinc, manganese and selenium were respectively added to the medium for 24 hours. The superoxide dismutase activity in the tissues and the cells was estimated. It was found that the SOD activity was enhanced by zinc and manganese and the effect of zinc on SOD activity was superior to that of manganese. We supposed that the enhance of the SOD activity was relative to the activation of the SOD apoenzymes. This experimental result indicated that the inhibitory effect of zinc and manganese on carcinogenesis was achieved by SOD and the elements might be considered a SOD activator.

Astrocytic effect of low molecular weight heparin-superoxide dismutase conjugate in interleukin-6 overexpressing mice following local cerebral ischemia

BACKGROUND： Studies have shown that low molecular weight heparin-superoxide dismutase conjugate exhibits a remarkable neuroprotective effect. OBJECTIVE： To investigate the effect of low molecular weight heparin-superoxide dismutase conjugate on astrocytes in an interleukin-6 （IL-6） overexpressing mice following local cerebral ischemia. DESIGN, TIME AND SETTING： Randomized, cytological, controlled, animal study was performed in the Department of Physiology and Neuroscience, Neurology and Biochemistry and Molecular Biology, Medical University of South Carolina from January 2005 to March 2005. MATERIALS： Nine IL-6 transgenic mice, irrespective of gender, were randomly divided into three groups： sham-operated, model, and treatment, with three mice in each group. With exception of the sham-operated group, right middle cerebral artery occlusion was induced in the mice. Expression of glial fibrillary acidic protein, an astrocyte marker, was determined by immunohistochemistry. Low molecular weight heparin-superoxide dismutase conjugate was purchased from Biochemistry and Biotechnique Institute, Shandong University. METHODS： Two minutes prior to ischemia induction, 0.5 mL/kg saline or 20 000 U/kg low molecular weight heparin-superoxide dismutase conjugate were administrated via the femoral artery in the model group and treatment group, respectively. The sham-operated group underwent the same protocols, with the exception of occlusion and treatment. MAIN OUTCOME MEASURES： The number of glial fibrillary acidic protein-positive cells was quantified under light microscopy （x200）. RESULTS： In the sham-operated group, there were a large number of astrocytes in the IL-6 transgenic mice. However, the cell bodies were small, and the branches were few and thin. The number of astrocytes in the model group was remarkably less than the sham-operated group. Compared to the model and sham-operated groups, the number of astrocytes significantly increased, and the cell body became larger, following treatment with low molecular weight heparin-superoxide dismutase conjugate. Astrocytes exhibited hypertrophy and hyperplasia, and the processes became longer and thicker. CONCLUSION： The low molecular weight heparin-superoxide dismutase conjugate may provide neuroprotection through astrocytic activation at the super-early stage of cerebral ischemia and reperfusion.

Combined effects of temperature and copper ion concentration on the superoxide dismutase activity in Crassostrea ariakensis

Superoxide dismutase（SOD） is a crucial antioxidant enzyme playing the first defense line in antioxidant pathways against reactive oxygen species in various organisms including marine invertebrates. There exist mainly two specific forms, Cu/Zn-SOD（SOD1） and Mn-SOD（SOD2）, in eukaryotes. SODs are known to be concurrently modulated by a variety of environmental stressors. By using central composite experimental design and response surface method, the joint effects of water temperature（18–34°C） and copper ion concentration（0.1–1.5 mg/L） on the total SOD activity in the digestive gland of Crassostrea ariakensis were studied. The results showed that the linear effect of temperature was highly significant（P〈0.01）, the quadratic effect of temperature was significant（P〈0.05）; the linear effect of copper ion concentration was not significant（P〉0.05）, while the quadratic effect of copper ion concentration was highly significant（P〈0.01）; the interactive effect of temperature and copper ion concentration was not significant（P〉0.05）; the effect of temperature was greater than that of copper ion concentration. The model equation of digestive gland SOD enzyme activity towards the two factors of interest was established, with R2 and predictive R2 as high as 0.961 6 and 0.820 7, respectively, suggesting that the goodness-offit to experimental data be very satisfactory, and could be applied to prediction of digestive gland SOD activity in C. ariakensis under the conditions of the experiment. Our results would be conducive to addressing the health of aquatic animals and/or to detecting environmental problems by taking SOD as a potential bioindicator.

Extracellular superoxide dismutase VdSOD5 is required for virulence in Verticillium dahliae

Plants produce reactive oxygen species(ROS) to defend pathogens. To counteract this attack, certain pathogens express superoxide dismutases(SODs) to scavenge host-derived ROS. However, the roles of SODs in Verticillium dahliae, an important vascular pathogen, are not clear. Our previous study has shown that a putative extracellular SOD(VdSOD5) of V. dahliae is significantly induced by culturing in cotton tissues, suggesting that VdSOD5 may play an important role in host–pathogen interactions and virulence. Here, we showed that VdSOD5 encoded a superoxide dismutase with a cofactor copper-binding site and a functional signal peptide that can conduct protein secretion in an invertase-mutated yeast strain. The mutations in VdSOD5(ΔVdSOD5) did not change the normal vegetative growth and conidial production but reduced the virulence of V. dahliae on susceptible host cotton. Further studies showed that the transcription of Vd SOD5 was significantly up-regulated during the early stage of infection, and the loss-of-function of VdSOD5 decreased culture filtrate and fungal tissue SOD activities of V. dahliae by 74 and 28%, respectively. Compared to the wild-type strain Vd991, the ΔVdSOD5 showed the same sensitivity to the intracellular ROS generator menadione. Furthermore, nitroblue tetrazolium(NBT) staining demonstrated that VdSOD5 functioned in the detoxification of superoxides generated by host roots during infection. These results suggest that VdSOD5 of V. dahliae is an important virulence factor, secreted out of cells to combat host-derived ROS.

Transcript profiles of mitochondrial and cytoplasmic manganese superoxide dismutases in Exopalaemon carinicauda under ammonia stress

Superoxide dismutase(SOD) is one of the most important antioxidant defense enzymes,and is considered as the first line against oxidative stress. In this study,we cloned a mitochondrial manganese(Mn) SOD( m Mn SOD) c DNA from the ridgetail white prawn E xopalaemon carinicauda by using rapid amplification of c DNA ends(RACE) methods. The full-length c DNA for m Mn SOD was 1 014-bp long,containing a 5′-untranslated region(UTR) of 37-bp,a 3′-UTR of 321-bp with a poly(A) tail,and included a 657-bp open reading frame encoding a protein of 218 amino acids with a 16-amino-acid signal peptide. The protein had a calculated molecular weight of 23.87 k Da and a theoretical isoelectric point of 6.75. The m Mn SOD sequence included two putative N-glycosylation sites(NHT and NLS),the Mn SOD signature sequence 1 80 DVWEHAYY 187,and four putative Mn binding sites(H48,H96,D180,and H184). Sequence comparison showed that the m Mn SOD deduced amino acid sequence of E. carinicauda shared 97%,95%,89%,84%,82%,72%,and 69% identity with that of M acrobrachium rosenbergii,M acrobrachium nipponense,Fenneropeneaus chinensis,Callinectes sapidus,P erisesarma b idens,D anio r erio,and Homo sapiens,resectively. Quantitative real-time RT-PCR analysis showed that m Mn SOD transcripts were present in all E. carinicauda tissues examined,with the highest levels in the hepatopancreas. During an ammonia stress treatment,the transcript levels of m Mn SOD and c Mn SOD were up-regulated at 12 h in hemocytes and at 24 h in the hepatopancreas. As the duration of the ammonia stress treatment extended to 72 h,the transcript levels of m Mn SOD and c Mn SOD significantly decreased both in hemocytes and hepatopancreas. These findings indicate that the SOD system is induced to respond to acute ammonia stress,and may be involved in environmental stress responses in E. carinicauda.

Effect of superoxide dismutase and malondialdehyde metabolic changes on carcinogenesis of gastric carcinoma

AIM: To investigate the relationship between the superoxide dismutase (SOD), malondialdehyde (MDA)metabolic changes and the gastric carcinogenesis.METHODS: The SOD activity and MDA content were measured in the gastric tissues from the focus center,peripheral and far-end areas of gastric carcinoma (n = 52)and gastric ulcer (n = 10). All the tissues were subjected to routine histological examinations and classifications.RESULTS: The SOD activity was greatly reduced but the MDA content was markedly increased in the center areas of the non-mucous gastric carcinoma (non-MGC); and the poorly differentiated gastric carcinoma varied. The SOD activity was gradually decreased and the MDA content was gradually increased in the tissues from the focus far-end, peripheral to center areas of non-MGC. Both of the SOD activity and the MDA content were significantly declined and were respectively at same low level in the tissues from the focus center, peripheral, and far-end area with the mucous gastric carcinoma (MGC). In contrast to the gastric ulcer and grade Ⅰ or Ⅱ of non-MGC, the same level of the SOD activity and the MDA content were found in the focus center areas. Between non-lvlGC (groups A-D) and gastric ulcer (group F), the differences of SOD activity and MDA content were very noticeable in the gastric tissues from the focus peripheral and far-end areas, in which the SOD activity showed noticeable increase and the MDA content showed noticeable decrease in the gastric ulcer.CONCLUSION: The active free radical reaction in the gastric tissues can induce the carcinogenesis of non-MGC.The utmost low ability of antioxidation in the gastric tissues can induce the carcinogenesis of MGC. The metabolic change of the free radicals centralized mostly in the center of ulcerated lesions only, which suggested the ability of antioxidation was declined only in these lesions. However,the metabolism of free radicals varied significantly and the ability of antioxidation declined not only in the local focus area but also in the abroad gastric tissues with gastric carcinoma.