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Biomedical subjects

S L Marklund

Publications and source records attributed to S L Marklund.

At least 127 records · Page 7Linked to original sources
PubMed1986

Ceruloplasmin, extracellular-superoxide dismutase, and scavenging of superoxide anion radicals.

Ceruloplasmin and extracellular-superoxide dismutase are similar in physical properties. Both are found in extracellular fluids and both are scavengers of the superoxide radical. The relationship between the two proteins was further explored in the present investigation. Ceruloplasmin preparations were found to be commonly contaminated with extracellular-superoxide dismutase. In one preparation, 80% of the superoxide dismutase activity was due to extracellular-superoxide dismutase. Ceruloplasmin, freed from contaminating superoxide dismutase, was found to catalytically dismute the superoxide anion radical with a rate constant of about 1.0 X 10(4) M-1 s-1 per copper atom. Under physiological conditions with a low rate of superoxide production, ceruloplasmin preferentially reacts stoichiometrically with the superoxide radical with a rate constant of about 2 X 10(5) M-1 s-1 per copper atom. Under such conditions, the reaction does not result in hydrogen peroxide formation. From the kinetic data obtained it was calculated that in normal human plasma, extracellular-superoxide dismutase will scavenge about twice as much superoxide as ceruloplasmin. Using immobilized antibodies toward extracellular superoxide dismutase and ceruloplasmin, no antigenic cross-reactivity between the two proteins could be detected.

Ceruloplasmin↗
PubMed1986

Plasma extracellular superoxide dismutase and erythrocyte Cu,Zn-containing superoxide dismutase in alcoholics treated with disulfiram.

Disulfiram has long been used in the treatment of chronic alcoholism. It is in vivo partially reduced to diethyldithiocarbamate, which is an efficient inhibitor of Cu,Zn-containing superoxide dismutase both in vitro and in vivo. The recently described extracellular superoxide dismutase is even more sensitive to diethyldithiocarbamate than Cu,Zn-superoxide dismutase. To test for the possibility that long term treatment with disulfiram leads to inhibiton of the superoxide dismutases, plasma extracellular superoxide dismutase and erythrocyte Cu,Zn-superoxide dismutase were determined in 12 disulfiram-treated alcoholics, and compared with 11 non-treated alcoholics and 19 healthy controls. Plasma extracellular superoxide dismutase was moderately reduced (about 20%) in the disulfiram-treated alcoholics as compared with the non-treated alcoholics and the healthy controls. No effect of disulfiram treatment on erythrocyte Cu,Zn-superoxide dismutase activity was demonstrated.

Adult↗
PubMed1986

Superoxide dismutase isoenzymes in cerebrospinal fluid and plasma from patients with neuronal ceroid-lipofuscinoses.

The neuronal ceroid-lipofuscinoses is a group of diseases characterized by a widespread accumulation in the body of pigments believed to be end-products of lipid-peroxidation damaged organelles. It was recently shown that cerebrospinal fluid from patients with infantile and juvenile neuronal ceroid-lipofuscinosis were less protective against superoxide radical-induced hydroxyl radical formation compared with controls. The content of superoxide dismutase isoenzymes in cerebrospinal fluid and in plasma from patients with different forms of neuronal ceroid-lipofuscinosis was analysed. No significant difference from controls could be demonstrated in samples from patients with juvenile neuronal ceroid-lipofuscinosis. The few samples from patients with infantile and late infantile neuronal ceroid-lipofuscinosis analysed all fell within the range defined by the controls.

Adult↗
PubMed1986

Superoxide dismutase isoenzymes of the synovial fluid in rheumatoid arthritis and in reactive arthritides.

The activity of superoxide dismutase isoenzymes was determined in knee joint synovial fluid from 21 patients with rheumatoid arthritis, nine patients with reactive arthritides, and from 17 patients before arthroscopy or arthrotomy for suspected meniscal or ligament injury (controls). Extracellular superoxide dismutase was the major isoenzyme and accounted for about 80% of the total superoxide dismutase activity in the controls. The pattern of the superoxide dismutase isoenzymes was significantly different in rheumatoid arthritis, extracellular (EC) superoxide dismutase being half, CuZn superoxide dismutase double, and the total superoxide dismutase activity a third lower than the activity in the synovial fluid of the controls. The superoxide dismutase activities were similar in synovial fluid from the controls and from the patients with reactive arthritides. The total superoxide dismutase activity was almost three times higher in control synovial fluid than in normal human plasma, but 300 times lower than in human tissues.

Arthritis↗
PubMed1985

Product of extracellular-superoxide dismutase catalysis.

Extracellular-superoxide dismutase is a tetrameric enzyme containing four copper atoms. It has previously been shown to catalyse the decay of the superoxide radical, but the resulting product was not determined. In a xanthine oxidase-xanthine system in which about 30% of the electron flux resulted in superoxide radical formation, accumulation of hydrogen peroxide was determined. Catalysis of superoxide radical decay by extracellular-superoxide dismutase was found to result in hydrogen peroxide formation. The catalysed reaction is thus identical to those of previously investigated superoxide dismutases. Human manganese superoxide dismutase was also found to dismute the superoxide radical to hydrogen peroxide and water.

Copper↗
PubMed1985

Superoxide dismutase isoenzymes in normal brains and in brains from patients with dementia of Alzheimer type.

CuZn superoxide dismutase and Mn superoxide dismutase were analysed in hypothalamus, nucleus caudatus, hippocampus and cortex gyrus cinguli from 14 patients with dementia of Alzheimer type and from 16 controls. Ample amounts of both enzymes were demonstrated in the brains and there was little difference between the various parts of the brain. There were only small differences in the enzymic activities between the two groups indicating that deficiencies of these enzymes are not a very likely cause of brain degeneration in dementias of Alzheimer type.

Age Factors↗
PubMed1984

Plasma EC-superoxide dismutase activity in insulin-dependent diabetic children.

Toxic oxygen-centered radicals have been linked to beta-cell damage brought about by some chemicals and might conceivably also be of importance in the pathogenesis of spontaneous insulin-dependent diabetes mellitus (IDDM). In several model systems, superoxide dismutase has been protective. The major protector against superoxide radicals in the extracellular space appears to be a recently discovered superoxide dismutase, EC-superoxide dismutase. This enzyme was analysed in plasma from children with insulin-dependent diabetes mellitus. The specimens were obtained from 8 patients with disease of recent onset and from 15 patients with disease of longer duration. There was no significant difference in EC-superoxide dismutase between the patients and controls.

Adolescent↗
PubMed1984

Extracellular superoxide dismutase and other superoxide dismutase isoenzymes in tissues from nine mammalian species.

The contents of extracellular superoxide dismutase, CuZn superoxide dismutase and Mn superoxide dismutase were determined in tissues from nine mammalian species. The pattern of CuZn superoxide dismutase distribution was similar in all species, with high activity in metabolically active organs such as liver and kidney and low activity in, for example, skeletal muscle. Mn superoxide dismutase activity was high in organs with high respiration, such as liver, kidney, and myocardium. Overall the Mn superoxide dismutase activity in organs was almost as high as the CuZn superoxide dismutase activity. The content of extracellular superoxide dismutase was, almost without exception, lower than the content of the other isoenzymes. The pattern of tissue distribution was distinctly different from those of CuZn superoxide dismutase and Mn superoxide dismutase. The tissue distribution of extracellular superoxide dismutase differed among species, but in general there was much in lungs and kidneys and little in skeletal muscle. In man, pig, sheep, cow, rabbit and mouse the overall tissue extracellular superoxide dismutase activities were similar to each other, whereas dog, cat and rat tissues contained distinctly less. There was no general correlation between the tissue extracellular superoxide dismutase activity of any of the various species and the variable plasma activity. The ratio between the plasma and the overall tissue activities was high, for some species over unity, providing further evidence for the notion that one role of extracellular superoxide dismutase is as a plasma protein.

Animals↗
PubMed1984

Properties of extracellular superoxide dismutase from human lung.

A further characterization of human extracellular superoxide dismutase is reported. The study was especially aimed at the interaction with substances known to interfere with CuZn superoxide dismutase and other superoxide dismutases. Extracellular superoxide dismutase is efficiently inhibited by cyanide and is about 3 times more sensitive than is human CuZn superoxide dismutase. The sensitivity to azide is much lower, but still about 3 times higher than that of human CuZn superoxide dismutase. Extracellular superoxide dismutase is about as rapidly inactivated by hydrogen peroxide as is CuZn superoxide dismutase. The sensitivity to diethyldithiocarbamate is very high and more than an order of magnitude larger than that of CuZn superoxide dismutase. Sodium dodecyl sulphate, under conditions suggested as being suitable for distinguishing between the insensitive CuZn superoxide dismutase and the sensitive Mn superoxide dismutase, efficiently inactivated extracellular superoxide dismutase. No antigenic similarities between extracellular superoxide dismutase and CuZn superoxide dismutase could be demonstrated. Anti-(extracellular superoxide dismutase) did not bind CuZn superoxide dismutase, and anti-(CuZn superoxide dismutase) did not bind extracellular superoxide dismutase.

Azides↗
PubMed1984

CuZn superoxide dismutase, Mn superoxide dismutase, catalase and glutathione peroxidase in glutathione-deficient human fibroblasts.

The effect of genetically determined glutathione deficiency on the fibroblast content of CuZn superoxide dismutase, Mn superoxide dismutase, catalase and glutathione peroxidase was investigated. No significant differences between glutathione-deficient and -proficient human fibroblasts were revealed. There was a large variation in the content of the investigated enzymes in fibroblasts grown and analysed on different occasions. Whereas the contents of CuZn superoxide dismutase, catalase and glutathione peroxidase did not deviate much from what has been found in other human cell-lines and tissues, the fibroblasts were found to contain exceptional amounts of Mn superoxide dismutase.

Adult↗
PubMed1984

Extracellular superoxide dismutase in human tissues and human cell lines.

Extracellular-superoxide dismutase is a tetrameric copper-containing glycoprotein that previously has been demonstrated to be the major superoxide dismutase of human extracellular fluids. The occurrence of this enzyme in various human tissues that were removed from two accidental death victims and in 19 different human cultured cell lines was determined. All investigated tissues were found to contain extracellular-superoxide dismutase. There was a larger variation between tissues in the concentration of this enzyme than in CuZn superoxide dismutase and Mn superoxide dismutase. No relation could be demonstrated between the content of extracellular-superoxide dismutase and the content of the other superoxide dismutase isoenzymes in the various tissues. In uterus there was more extracellular-superoxide dismutase than Mn superoxide dismutase, but in all other tissues the content of extracellular-superoxide dismutase was lower than the content of the other isoenzymes. The concentration of extracellular-superoxide dismutase was higher in all investigated human tissues than in human plasma. 19 human cultured cell lines were found to be devoid of or to contain very little extracellular-superoxide dismutase. Most tissues contained more extracellular-superoxide dismutase than did the investigated cell lines.

Animals↗
PubMed1984

Effect of long-term penicillamine therapy on erythrocyte CuZn superoxide dismutase activity.

The effect of long-term penicillamine therapy on erythrocyte CuZn superoxide dismutase activity was investigated. For comparison the serum ceruloplasmin and serum copper contents were also analysed. Seven of the 11 penicillamine-treated patients had CuZn superoxide dismutase activities below the reference interval of the parameter. Levels down to about 50% of the mean of controls were observed in several cases. In five and in four of the 11 patients respectively decreases in serum ceruloplasmin and serum copper were found. Whereas among the penicillamine-treated patients there was a good correlation between serum ceruloplasmin and serum copper, the correlation between these parameters and erythrocyte CuZn superoxide dismutase was only fair. Erythrocyte CuZn superoxide dismutase is probably a suitable parameter for monitoring intracellular copper availability during penicillamine therapy.

Adult↗
PubMed1984

Radiation resistance and the CuZn superoxide dismutase, Mn superoxide dismutase, catalase, and glutathione peroxidase activities of seven human cell lines.

CuZn superoxide dismutase, Mn superoxide dismutase, catalase, and glutathione peroxidase form the primary enzymic defense against toxic oxygen reduction metabolites in cells. To test the importance of these protective enzymes in the cellular radiation response, the enzymic activities of seven different human cell lines were determined in parallel with their clonogenic survival characteristics. A positive correlation between the content of glutathione peroxidase in cell lines and their extrapolation numbers (n) and quasithreshold doses (Dq) was detected. Between the cellular contents of the other enzymes and D0, n, and Dq no positive correlations could be established. An interesting finding was a very high Mn superoxide dismutase content in a malignant mesothelioma cell line P7, which had an extremely high D0, 5.0 Gy.

Catalase↗
PubMed1983

Opposite effects of two metal-chelators on alloxan-induced diabetes in mice.

Alloxan diabetes may be mediated by an iron-catalyzed formation of hydroxyl radicals. The iron chelators desferrioxamine and diethylenetriaminepentacetic acid (DETAPAC) which inhibit hydroxyl radical formation in vitro were tested against alloxan diabetes in mice. DETAPAC inhibited while desferrioxamine stimulated the hyperglycemic response to alloxan. The diverging treatment results are discussed.

Alloxan↗
PubMed1983

Superoxide dismutase activity in brains from chronic alcoholics.

CuZn superoxide dismutase (SOD) and Mn SOD activities were analyzed in hypothalamus, nucleus caudatus, hippocampus and cortex gyrus cinguli from 12 chronic alcoholics and from 16 controls. The CuZn SOD activities were slightly lower and the Mn SOD activities were slightly higher in the brain pieces from chronic alcoholics compared to the controls. The slight differences found can hardly be assigned etiological importance in the degenerative processes in brain tissue connected with chronic alcoholism.

Adult↗