Serum Extracellular Superoxide Dismutase Research Articles

Estimating Pulmonary Function, Interleukin-6 (IL-6), And Superoxide Dismutase-3 (EC-SOD3) Levels in Patients with Chronic Bronchial Asthma on Curcumin Adjuvant Therapy

This study was designed to evaluate the effectiveness of curcumin supplement as antioxidant and anti-inflammatory in patients with chronic bronchial asthma. Forty patients diagnosed with chronic bronchial asthma were enrolled in this study and allocated into group (1) patients assigned to receive conventional therapy of asthma, and group (2) patient assigned to receive conventional therapy of asthma combined with 750 mg curcumin supplement twice daily for two months. Pulmonary function test, asthma control test, serum interleukin-6 and serum extracellular super oxide dismutase 3 were measured before and after two months in both study groups. After two months, the mean values of pulmonary function test (spirometry) and asthma control score showed significant increase compared to pre-treatment values in group 2 patients (P<0.01). Moreover, there was marked decrease in the level of interleukin-6 in group 2 patients after two months (p< 0.05) compared to the increased in group 1 patients. The mean level of super oxide dismutase 3 didn’t show any increase in both study groups after treatment. Curcumin supplement produced improvement in pulmonary function of patients with chronic bronchial asthma along with the reduction in inflammatory status. No change in endogenous oxidative status after curcumin supplementation.

Comparison of Thymulin Activity with Other Measures of Marginal Zinc Deficiency.

Activity of the immunoregulatory peptide thymulin reflects differences in zinc status. This study compared thymulin activity with four other zinc status measures in rats fed zinc at either 5 or 25ppm. Rats fed the lower zinc showed the following results compared with rats with adequate zinc intake: serum thymulin activity 61% lower, serum zinc 31% lower, serum extracellular superoxide dismutase 18% lower, serum 5'-nucleotidase activity 26% lower, and liver metallothionein 28% lower. Thus, thymulin activities showed more sensitivity to restricted zinc intake than did four other parameters.

Serum Extracellular Superoxide Dismutase Is Associated with Diabetic Retinopathy Stage in Chinese Patients with Type 2 Diabetes Mellitus.

Extracellular superoxide dismutase (ecSOD) is the major extracellular scavenger of reactive oxygen species and associated with the diabetic complication in patients with type 2 diabetes mellitus (T2DM). We aimed to investigate the serum ecSOD activity in Chinese patients with different stages of diabetic retinopathy (DR) and evaluate the association between the serum ecSOD activity and the severity of DR. A total of 343 T2DM patients were categorized into three groups: nondiabetic retinopathy (NDR) group, nonproliferative diabetic retinopathy (NPDR) group, and proliferative diabetic retinopathy (PDR) group. Serum ecSOD activities were measured by the autoxidation of the pyrogallol method. In this study, 271, 46, and 26 patients were enrolled in the NDR, NPDR, and PDR groups, respectively. We found a significantly decreased trend of serum ecSOD activity among NDR subjects (118.0 ± 11.5 U/mL) compared to NPDR subjects (108.5 ± 11.9 U/mL) (P < 0.001) and NPDR subjects compared to PDR subjects (102.7 ± 12.4 U/mL) (P = 0.041). Serum ecSOD activity was an independent risk factor for DR (OR = 0.920, P < 0.001) and was associated with the progression of DR. Serum ecSOD activity might be a biomarker for DR screening and evaluation of the clinical severity of DR in Chinese T2DM patients.

Lower serum extracellular superoxide dismutase levels are associated with polyneuropathy in recent-onset diabetes

Increased oxidative stress is implicated in the pathogenesis of experimental diabetic neuropathy, but translational evidence in recent-onset diabetes is scarce. We aimed to determine whether markers of systemic oxidative stress are associated with diabetic sensorimotor polyneuropathy (DSPN) in recent-onset diabetes. In this cross-sectional study, we measured serum concentrations of extracellular superoxide dismutase (SOD3), thiobarbituric acid reactive substances (TBARS), and reduced glutathione (GSH) in 107 type 1 and 215 type 2 diabetes patients from the German Diabetes Study baseline cohort and 37 glucose-tolerant individuals (controls). DSPN was defined by electrophysiological and clinical criteria (Toronto Consensus, 2011). SOD3 and GSH concentrations were lower in individuals with type 1 and type 2 diabetes compared with concentrations in controls (P<0.0001). In contrast, the TBARS concentration was higher in participants with type 1 diabetes and type 2 diabetes compared with levels in controls (P<0.0001). In addition, the SOD3 concentration was higher in participants with type 1 diabetes compared to concentrations in those with type 2 diabetes (P<0.0001). A low SOD3 concentration was associated with DSPN in individuals with type 1 diabetes (β=−0.306, P=0.002), type 2 diabetes (β=−0.164, P=0.017), and in both groups combined (β=−0.206, P=0.0003). Lower SOD3 concentrations were associated with decreased motor nerve conduction velocity (NCV) in men and, to a lesser degree, with reduced sensory NCV in women with diabetes. In conclusion, several biomarkers of oxidative stress are altered in recent-onset diabetes, with only a lower SOD3 concentration being linked to the presence of DSPN, suggesting a role for reduced extracellular antioxidative defense against superoxide in the early development of DSPN.

Decreased serum extracellular superoxide dismutase activity is associated with albuminuria in Chinese patients with type 2 diabetes mellitus.

The aim of this study was to determine the activity of serum extracellular superoxide dismutase (ecSOD) in patients with type 2 diabetes mellitus (T2DM) and healthy subjects, and to determine the prospective association between baseline serum ecSOD activity and the subsequent risk of albuminuria progression in a cohort of Chinese T2DM patients. A total of 458 T2DM patients and 100 healthy subjects were assessed. After a median follow-up of 7.7months, 319 patients with baseline normoalbuminuria (urinary albumin-to-creatinine ratio [UACR] <30mg/g) and 77 patients with baseline microalbuminuria (UACR=30-299mg/g) were divided into progression and non-progression groups according to UACR changes. Serum ecSOD activity was determined by the autoxidation ofpyrogallol method. Multivariate Cox regression analysis was used for investigating the predictors for albuminuria progression. Compared with healthy controls (174.5±25.1U/mL), serum ecSOD activity significantly decreased in T2DM patients with normoalbuminuria (114.9±13.2U/mL), with microalbuminuria (106.6±16.3U/mL), and with macroalbuminuria (97.1±18.2U/mL) (all P<0.001). Serum ecSOD activity was associated with albuminuria (odds ratio [OR]=1.028, P=0.004) in T2DM patients. Baseline serum ecSOD activity (hazard ratio [HR]=0.902, 95% CI 0.877-0.928, P<0.001) was an independent predictor for albuminuria progression. Serum ecSOD activity may be useful for predicting the future risk of albuminuria progression in Chinese T2DM patients.

STUDY THE POTENTIAL ANTIOXIDANT EFFECT OF VITAMIN D3 SUPPLEMENTATION ON THE LEVEL OF EXTRACELLULAR SUPEROXIDE DISMUTASE IN ASTHMATIC PATIENTS

Objective: This study was designed to evaluate the potential antioxidant effect of vitamin D3 supplementation in chronic asthma patients.Methods: A total of 44 candidate patients were diagnosed with asthma allocated as Group 1 includes 20 patients assigned to receive conventional therapy for asthma and Group 2 includes 24 patients assigned to receive conventional therapy for asthma plus 2000 IU vitamin D3 tablet for 3-month period. Furthermore, 30 apparently healthy subjects were included in the study as a control group. Pulmonary function test, serum 25-hydroxy vitamin D levels, serum extracellular superoxide dismutase (SOD3) levels were measured before and after 3 months therapy.Results: The mean forced expiratory volume in 1 second (FEV1) both the measured and the percentage of predicted value showed a highly significant increase after 3 months treatment compared to pre-treatment value in both study groups (p&lt;0.01). When compared to pre-treatment value, there was no significant increase in forced expiratory volume in one second to forced vital capacity ratio (FEV1/FVC) in Group 1 (p&gt;0.05), nevertheless, Group 2 showed highly significant increase after 3 months (p&lt;0.01). Approximately, 90-96% of adult asthmatic patients revealed vitamin D deficiency (&lt;20 ng/ml). Post-treatment with adjuvant vitamin D3 therapy, 25% of patients obtained acceptable level of vitamin D sufficiency (≥30 ng/ml). After 3 months of the treatment, Group 1 patients showed a significant decrease in mean SOD3 level compared to pre-treatment level (p&lt;0.05), while Group 2 patients showed a significant increase in mean SOD3 level compared to pre-treatment level (p&lt;0.05).Conclusion: Most of the asthmatic patients revealed vitamin D deficiency and supplementation with vitamin D3 reduce oxidative stress burden in those patients.

Markers of inflammation and antioxidant enzyme activities in restenosis following percutaneous coronary intervention

The efficacy of percutaneous coronary intervention (PCI) is often compromised by the need for repeat revascularization, because of restenosis development. Numerous studies have tried to establish the predictive value of different biochemical markers of restenosis, with conflicting results. The aim of this study was to assess the prognostic significance of inflammatory and lipid markers, and major antioxidant enzyme activity for the development of in-stent restenosis (ISR) following PCI. Serum high sensitive C-reactive protein (hs-CRP), soluble intercellular cell adhesion molecule-1 (sICAM-1), transforming growth factor-beta (TGF-?), lipoprotein(a) and oxidized low-density lipoprotein (oxLDL) levels, as well as serum extracellular superoxide dismutase (EC-SOD) and catalase (CAT) activity were determined in 44 patients before stent implantation procedure, and after 6-month follow-up. Results after follow-up revealed that, in patients that developed angiografically confirmed ISR, the increase in serum hs-CRP levels was significanty higher, compared to those without stenosis. Stent implantation induced compensatory increase in serum antioxidant enzyme activities at follow-up, with significantly lower CAT activity in patients with ISR, possibly contributing to stenosis development. No significant changes in circulating levels of ICAM-1, TGF-?, oxLDL and Lp(a) were observed between the groups. In conclusion, serum hs-CRP level and CAT activity may be considered as useful biochemical markers for monitoring patients during follow-up after stent implantation.

Comparison of thymulin activity to other measures in marginally zinc deficient rats (1043.11)

Activity of the thymus derived, immunoregulatory peptide thymulin has shown high sensitivity to zinc status in humans. However, this research has generally been done for people with the confounding effects of various health issues. In contrast, a study was done on healthy, semi‐mature growing rats where the only variable was adequate zinc status versus a short term, moderate restriction of zinc intake. After 2 weeks of being fed a diet with 5 ppm zinc, rats showed a mean serum zinc value that was 31% lower than for rats fed 27 ppm zinc. A much bigger mean percent difference of 61% was seen for serum thymulin activity. This activity was determined by a rosette formation assay that uses sheep erythrocytes plus spleen cells from thymectomized mice. Activity was restored to 100% of normal in vitro by adding zinc to the assay. Body weight was lower in the rats fed lower zinc (187 + 5 g vs 242 + 13), but total food intake was not much lower, and was the same per body weight. Serum extracellular superoxide dismutase activity was 18% lower in the low zinc group, and serum 5’‐nucleotidase activity was 26% lower. In addition, liver metallothionein in the low zinc group was about 27% lower than in the zinc adequate group. In conclusion, in rats, a marginal zinc deficiency, with no other confounding factors,produced a larger effect on thymulin activities than on a number of other parameters.

Relationship between insulin resistance and inflammatory markers and anti-inflammatory effect of losartan in patients with type 2 diabetes and hypertension

Background It is now well established that vascular inflammation and endothelial dysfunction associated with cardiovascular diseases contributes to insulin resistance. Methods We investigated the relationship between the homeostasis model assessment-insulin resistance index (HOMA-R) and various serum inflammatory markers and the effect of losartan on serum concentrations of these markers in patients with type 2 diabetes and hypertension. The patients were divided into 2 groups according to the value of HOMA-R with 60 patients with values = 2.4 in Group A and 44 patients with values > 2.5 in Group B. The variables were measured at baseline and after 6 months of treatment with losartan (50 mg/day). Results The HOMA-R concentrations were positively related to TNF-α ( r = 0.336, P < 0.01) and inversely related to adiponectin ( r = − 0.405, P < 0.01) and extracellular-superoxide dismutase (EC-SOD) ( r = − 0.452, P < 0.01). Stepwise multiple regression analysis showed a significant relationship between HOMA-R and adiponectin ( F = 8.74) and EC-SOD ( F = 14.39). In Group B, losartan treatment significantly increased the serum concentrations of EC-SOD and adiponectin and decreased TNF-α and HOMA-R. Conclusion Serum EC-SOD concentrations may be a sensitive biochemical marker of insulin resistance in patients with type 2 diabetes and hypertension and that losartan improves insulin sensitivity by increasing EC-SOD and adiponectin production and decreasing TNF-α production.

Serum extracellular superoxide dismutase in patients with type 2 diabetes: relationship to the development of micro- and macrovascular complications.

The aim of this study was to determine the distribution of serum extracellular superoxide dismutase (EC-SOD) concentrations in patients with type 2 diabetes and to assess whether increased EC-SOD concentration is associated with the development of diabetic vascular complications. Serum EC-SOD concentrations were determined in 222 patients with type 2 diabetes and 75 healthy control subjects by an enzyme-linked immunosorbent assay. All subjects had the EC-SOD domain genotyped. The serum EC-SOD concentrations showed a distinct bimodal distribution in both patients with diabetes and control subjects. All subjects with the high-level phenotype carried the Arg213Gly mutation. The frequency of this variant was similar in the diabetes and control groups. Within the group of subjects with the common EC-SOD phenotype, the serum EC-SOD concentration (mean +/- SE) was significantly higher in patients with type 2 diabetes (99.3 +/- 1.3 ng/ml) compared with the control subjects (68.4 +/- 2.3 ng/ml, P < 0.01). Stepwise multiple regression analysis of the data from the diabetic common phenotype group showed a significant relationship between serum EC-SOD concentration and duration of diabetes (F = 5.31), carotid artery intimal-media thickness (F = 8.24), and severity of nephropathy (F = 16.05) and retinopathy (F = 4.43). We observed a strong relationship between the serum concentration of EC-SOD and the severity of both micro- and macrovascular diabetic complications. These findings suggest that serum EC-SOD concentration levels may be a marker of vascular injury, possibly reflecting hyperglycemia-induced oxidative injury to the vascular endothelium and decreased binding of EC-SOD to the vascular wall.

Extracellular superoxide dismutase following cerebral ischemia in mice.

We describe the changes in extracellular superoxide dismutase (EC-SOD) following cerebral ischemia in mice. Mice were subjected to transient forebrain ischemia and reperfusion. The measurements of EC-SOD using ELISA showed increased brain EC-SOD after 24 h of reperfusion. The immunohistochemical examination showed that EC-SOD immunoreactivity in cortical and striatal capillary wall was conspicuous after 3 h. EC-SOD immunoreactivity was also noted in cortical neurons after 24 h. Northern blot analysis showed an increased EC-SOD mRNA expression in the brain after 24 h. In situ hybridization study demonstrated no mRNA expression of EC-SOD following ischemia and reperfusion in the capillary wall. These findings suggest that serum EC-SOD might accumulate on brain endothelial cells, while cortical neurons produce EC-SOD themselves after cerebral ischemia with reperfusion.

Changes in dietary zinc and copper affect zinc-status indicators of postmenopausal women, notably, extracellular superoxide dismutase and amyloid precursor proteins

Zinc is an essential trace element for human health and well-being; however, methods currently available for the assessment of zinc status in humans are unsatisfactory. The objective was to critically evaluate the use of various indicators of zinc status in humans in a controlled metabolic ward study. Indicators of zinc status were measured in 25 healthy postmenopausal women aged 64.9 +/- 6.7 y. After a 10-d equilibration period, volunteers consumed a diet with either a low (1 mg/d; n = 12) or a high (3 mg/d; n = 13) copper content based on a total energy content of 8.4 MJ. They received the same amount of copper throughout the study. Both groups were fed the basal diet (3 mg Zn/d) with no zinc supplement for one 90-d period, and the diet supplemented with 50 mg Zn/d for another 90-d period. Zinc supplementation significantly increased (P < 0.0001) extracellular but not erythrocyte superoxide dismutase activity. This increase was more apparent when subjects were fed the low-copper diet. Zinc supplementation in combination with the low-copper diet significantly decreased (P < 0.01) amyloid precursor protein expression in platelets. Other indicators of zinc status that were significantly elevated after zinc supplementation were as follows: plasma zinc and free thyroxine concentrations and mononuclear 5'-nucleotidase activity. The measurement of serum extracellular superoxide dismutase activity may be useful as a marker for the functional assessment of zinc status in humans.

Increase of urinary extracellular-superoxide dismutase level correlated with cyclic adenosine monophosphate

Extracellular superoxide dismutase (EC-SOD) is a secretory protein that is the major SOD isozyme in extracellular fluids. Plasma EC-SOD levels are distributed in two discrete groups with the rare group having an enzyme with glycine instead of arginine-213, which causes a 10-fold higher serum level. Within the common phenotype group, the urinary EC-SOD level was significantly correlated with the urinary excretion of N-acetyl-β- D-glucosaminidase (NAG), but not with serum EC-SOD. EC-SOD appears not to be leaked from the plasma by glomerular filtration, but rather to be secreted from the renal tubule or its surrounding tissues. The urinary EC-SOD level was also significantly correlated with the urinary cyclic adenosine monophosphate (cAMP) level. cAMP analogues and adenylate cyclase modulators significantly stimulated the expression of EC-SOD but not other SOD isozymes in cultured fibroblast cell lines. Moreover, injection of parathyroid hormone, in Ellsworth-Howard tests, increased urinary EC-SOD accompanied with the elevations of urinary cAMP and NAG. Together these observations suggest that factor(s) that stimulate the adenylate cyclase-cAMP system regulate the urinary EC-SOD level.

Serum extracellular superoxide dismutase activity as an indicator of zinc status in humans.

The present study focused on whether serum extracellular superoxide dimutase (EC-SOD) activity can be used as a functional indicator of marginal zinc deficiency in humans. Subjects in this study were 444 healthy adults over 30 yr of age living a normal rural life in Kyunggi province, Korea. The mean dietary zinc intake of subjects obtained from one 24-h recall was 6.41 +/- 4.35 mg and the average serum zinc concentration of the subjects was 11.06 +/- 2.44 micromol/L. Subjects were divided into three groups by serum zinc concentrations: adequate (serum zinc >10.7 micromol/L), low (serum zinc 9.0-10.7 micromol/L), and very low (serum zinc <9.0 micromol/L) groups. A total of 50 subjects were selected from the three groups for analysis of EC-SOD activities. The EC-SOD activity of subjects increased with increasing serum zinc concentrations, and the activities of the three groups were significantly different as indicated by the Kruskal-Wallis test (p = 0.0239). Also, serum EC-SOD activities were significantly correlated with serum zinc concentrations (r = 0.289, p = 0.04). Serum EC-SOD activities, however, were not significantly correlated to the dietary zinc intakes. In conclusion, these results show that EC-SOD activities are decreased in subjects with low serum zinc concentrations and suggest that EC-SOD activity may be a functional indicator of zinc nutritional status in humans.

Familial amyloidotic polyneuropathy type I with extracellular superoxide dismutase mutation: A case report

We report an autopsy case of familial amyloidotic polyneuropathy (FAP) Type I with mutations in both transthyretin (TTR) and extracellular superoxide dismutase (EC-SOD). This patient started to develop peripheral neuropathy at age 25, followed by cardiac, renal, and autonomic nervous system failure due to massive amyloid deposition. Thirteen years after the initial symptoms, he died of septic shock. Autopsy revealed suppurative peritonitis, multiple abscesses in the bile ducts and urinary tract, and more marked amyloid deposition than commonly seen in FAP Amyloid deposition occurred in various organs and tissues, especially prominently around blood vessels and in interstitial tissues, and was demonstrated immunohistochemically to be composed of TTR but not amyloid A (AA) and not amyloid L (AL) proteins. The serum EC-SOD content of the patient was 10 fold higher than those seen often in other FAP patients and in healthy controls. Genetic analysis demonstrated the single amino acid substitutions in Val30Met TTR and Arg213G1y EC-SOD. Since these data suggest the dissociation of EC-SOD from the vascular wall, massive amyloid deposition in the present case may be related to increased oxidative stress in loco.

An Arginine-213 to Glycine Mutation in Human Extracellular-Superoxide Dismutase Reduces Susceptibility to Trypsin-Like Proteinases

Molecular genetic studies of extracellular-superoxide dismutase (EC-SOD) have shown that individuals with high serum EC-SOD content have a single base substitution generating the exchange of glycine for arginine-213 (R213G) in the heparin-binding domain of this enzyme [Sandström, J. et al. (1994) J. Biol. Chem. 269, 19163-19166], which causes the impairment of its binding ability to endothelial cell surface [Adachi, T. et al. (1996) Biochem. J. 313, 235-239]. Serum EC-SOD in healthy individuals without the above mutation is heterogeneous with regard to heparin affinity and consists of five fractions, forms (I) to (V), of which (IV) and (V) are the main fractions with high affinity for heparin [Adachi, T. et al. (1995) J. Biochem. 117, 586-590], whereas the major fraction in hemodialysis patients was serum EC-SOD form (I), which is thought to be the proteolytic truncated form. On the other hand, serum EC-SOD in both healthy individuals and hemodialysis patients with the R213G mutation consisted mainly of the high heparin-affinity type. This observation suggests that the susceptibility of EC-SOD to proteinases is reduced by the R213G mutation. The affinity of normal EC-SOD (n-EC-SOD) for heparin decreased by the treatment with trypsin, accompanied by a reduction in the molecular mass. The IC50 of trypsin for the heparin affinity of R213G mutant EC-SOD (m-EC-SOD) was 0.15 microgram/ml, fivefold that for n-EC-SOD. Heparin affinity of n-EC-SOD was again more susceptible to neutrophils than that of m-EC-SOD. These results suggested that m-EC-SOD is more resistant to trypsin and neutrophil-release trypsin-like proteinases than n-EC-SOD, which causes the heparin affinity of serum EC-SOD to differ in individuals with and without the R213G mutation.

Substitution of glycine for arginine-213 in extracellular-superoxide dismutase impairs affinity for heparin and endothelial cell surface

Extracellular-superoxide dismutase (EC-SOD) levels in sera divide into two discontinuous groups: a low-level group below 400 ng/ml and a high-level group above 400 ng/ml [Adachi, Nakamura, Yamada, Futenma, Kato and Hirano (1994) Clin. Chim. Acta 229, 123-131]. Molecular genetic studies have shown that the donors in the high-level group have a single base substitution generating the exchange of glycine for arginine-213 (R213G) in the heparin-binding domain of EC-SOD [Sandström, Nilsson, Karlsson and Marklund (1994) J. Biol. Chem. 269, 19163-19166; Yamada, Yamada, Adachi, Goto, Ogasawara, Futenma, Kitano, Hirano and Kato (1995) Jpn. J. Hum. Genet. 40, 177-184]. The serum EC-SOD level in homozygote subjects was significantly higher than that in heterozygotes and in normal subjects. Serum EC-SOD from heterozygotes and homozygotes had equally decreased affinity for heparin, as judged by heparin-HPLC, as compared with that from normal donors. This result suggests that the serum EC-SOD in heterozygotes was mainly composed of the mutant form which has reduced heparin affinity. On the other hand, fibroblast cells derived from heterozygote subjects generated mRNA of both normal and mutant EC-SOD (m-EC-SOD), and expressed the corresponding proteins. EC-SOD is a tetrameric enzyme, and in heterozygote donors would be heterogeneous with regard to the constitution of normal and mutant subunits. The enzyme form consisting of only mutant subunits, the form with the weakest heparin affinity, can be preferentially driven out to the plasma phase, because EC-SOD in the vasculature exists in equilibrium between plasma and the endothelial cell surface. The binding of m-EC-SOD to bovine aortic endothelial cells was about 50-fold less than that of normal EC-SOD. This result suggests that the binding of m-EC-SOD to vascular endothelial cells is much decreased in vivo, which causes a high level of serum EC-SOD.

Molecular analysis of extracellular-superoxide dismutase gene associated with high level in serum.

Extracellular-superoxide dismutase (EC-SOD) is one of the SOD isozymes mainly distributed in the extracellular fluid. In the vascular system, it is located on the endothelial cell surface according to studies on the heparin binding capacity. By measurement of serum EC-SOD levels of Japanese in healthy persons (n = 103) and hemodialysis patients (n = 150), 7 healthy subjects and 24 hemodialysis patients were classified into group II associated with high EC-SOD levels. By molecular analysis of the EC-SOD coding region from the group II individuals in Sweden, a single nucleotide substitution of G to C generating an amino acid change of arginine to glycine has been identified in the region associated with the heparin affinity of the enzyme. The same mutation was detected in the Japanese as a homozygote in both alleles of 2 hemodialysis patients and as a heterozygote in one allele of all the healthy group II individuals and 17 hemodialysis patients. The amino acid substitution may result in the decrease of the heparin affinity which is favorable for the existence of EC-SOD in the serum.

Quantitative and qualitative changes of extracellular-superoxide dismutase in patients with various diseases

Extracellular-superoxide dismutase (EC-SOD) is a secretory glycoprotein that is the major SOD isozyme in extracellular fluids. It has previously been shown that EC-SOD levels in sera from healthy persons are clearly divided into two discontinuous groups: a lower group (named Group I, below 120 ng/ml) and a higher group (Group II, above 400 ng/ml). The family studies have shown that the high EC-SOD level in healthy persons is genetically transmitted. We report here on the EC-SOD levels in the sera of patients with various diseases. The EC-SOD levels were distinctly higher in patients with renal diseases and moderately higher in liver diseases and diabetes than those in normal healthy persons. In cerebrovascular diseases, heart diseases and acute digestive diseases, significant differences of EC-SOD were not observed. In patients with renal diseases, the increase of EC-SOD was accompanied by the lack of renal function. Serum EC-SOD in Group I healthy persons is known to be heterogeneous with regard to heparin affinity and can be separated into three fractions: A without affinity, B with weak affinity and C with relatively strong heparin affinity, whereas the EC-SOD in Group II is mainly one fraction of C-type. Also in the case of hemodialysis patients, serum EC-SOD in Group I or Group I' (~120–400 ng/ml) was divided into three fractions. EC-SOD in Group II showed two different profiles on heparin-Sepharose column chromatographies: one consisted mainly of EC-SOD C and the other consisted of EC-SOD A and C. It is probable that the high serum EC-SOD level in hemodialysis patients was due to two possible factors: the genetic transmitted factor and unknown pathophysiological factor(s).

Quantitative analysis of extracellular-superoxide dismutase in serum and urine by ELISA with monoclonal antibody

The Superoxide anion has been implicated in a wide range of diseases. The major protector against Superoxide anion in the extracellular space is extracellular-superoxide dismutase (EC-SOD). EC-SOD is the major SOD isozyme in plasma and forms an equilibrium between the plasma phase and heparan sulfate proteoglycan on the surface of the endothelium. An ELISA method for the measurement of human EC-SOD with monoclonal antibody was established. The proposed method had a high sensitivity (assay range, 0.05–50 ng/ml), good recovery (recovery percentage, 96.9 ± 5.6%) and reproducibility (within-day assay, C. V. = 8.6 ~ 10.2%; between-day assay, C. V. = 6.5 ~ 11.7%). EC-SOD levels in sera from healthy persons are clearly divided into two groups: a lower group (Group I, below 120 ng/ml, n = 146) and higher group (Group II, above 400 ng/ml, n = 10). The EC-SOD in Group I were almost normally distributed and the mean level was 55.8 ± 18.8 ng/ml. The serum EC-SOD level assayed by ELISA correlated well with serum SOD activity. The serum EC-SOD in Group I is heterogeneous with regard to affinity for heparin-Sepharose and could be separated into three approximately equal fractions, Whereas the EC-SOD in Group II is mainly one fraction with a high affinity for the column. The apparent molecular weight and carbohydrate structure of serum EC-SOD in Group II are identical to those in Group I. The high EC-SOD level in sera from some individuals may reflect the excessive stimulation of EC-SOD synthesis in vivo or the growth of selected cells in vivo, because EC-SOD is known to be expressed by a few cell types in vivo as a high-heparin-affinity subtype.