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Biomedical subjects

S L Marklund

Publications and source records attributed to S L Marklund.

138 records · Page 8Linked to original sources
PubMed1983

CuZn superoxide dismutase, Mn superoxide dismutase, catalase and glutathione peroxidase in lymphocytes and erythrocytes in insulin-dependent diabetic children.

CuZn superoxide dismutase, Mn superoxide dismutase, catalase and glutathione peroxidase activities in lymphocytes and erythrocytes were studied in 9 children with insulin-dependent diabetes mellitus (IDDM) as well as in 21 healthy children. The mean erythrocyte CuZn superoxide dismutase and glutathione peroxidase were statistically significantly lower in the IDDM group compared with the controls although almost all IDDM results fell within the mean +/- 2 SD limits of the controls. The small differences found can hardly be assigned biological significance. Erythrocyte catalase as well as lymphocyte CuZn superoxide dismutase and Mn superoxide dismutase did not differ from the controls.

Adolescent↗
PubMed1982

Superoxide dismutase in extracellular fluids.

Serum from healthy volunteers contained very little CuZn superoxide dismutase. Larger amounts were found in serum from patients with impaired renal function, and there was a good correlation between serum creatinine and serum CuZn superoxide dismutase content. Almost all superoxide dismutase activity of human serum was cyanide sensitive, and was found to be given by a factor(s) with a molecular mass of approximately 130000. The factor was found in all human extracellular fluids investigated: plasma, serum, lymph, ascites and cerebrospinal fluid. The factor was not recognized by radioimmunoassay for human CuZn superoxide dismutase, and it was not inhibited by rabbit antibodies against human CuZn superoxide dismutase. A similar high-molecular mass factor was found in plasma from all mammals investigated: horse, cow, pig, dog, cat, rabbit, rat and mouse. The activities differed much among species and were mostly higher than those found in human serum/plasma.

Animals↗
PubMed1982

Human copper-containing superoxide dismutase of high molecular weight.

A superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.15.1.1), distinct from previously known superoxide dismutases, has been isolated from human lung tissue. It is probably of the same nature as a previously demonstrated high molecular weight superoxide dismutating factor in human extracellular fluids. The enzyme has a molecular weight around 135,000 and is composed of four equal noncovalently bound subunits. Each molecule appears to have four copper atoms. No iron or manganese was found in the enzyme. Cyanide inhibits the enzyme efficiently. The enzyme brings about a first-order dismutation of the superoxide radical, the rate constant for the catalyzed reaction being about 1 X 10(9) M-1 s-1 per copper atom. The enzyme has hydrophobic properties. Affinity for various lectins indicates the presence of carbohydrate. Upon chromatography on heparin-Sepharose it is divided into three fractions, one with no, one with weak, and one with strong affinity for heparin.

Amino Acids↗
PubMed1982

Copper- and zinc-containing superoxide dismutase, manganese-containing superoxide dismutase, catalase, and glutathione peroxidase in normal and neoplastic human cell lines and normal human tissues.

Copper- and zinc-containing superoxide dismutase, manganese-containing superoxide dismutase, catalase, and glutathione peroxidase form the primary enzymic defense against toxic oxygen reduction metabolites. Such metabolites have been implicated in the damage brought about by ionizing radiation, as well as in the effects of several cytostatic compounds. These enzymes were analyzed in 31 different human normal diploid and neoplastic cell lines and for comparison in 15 normal human tissues. The copper- and zinc-containing superoxide dismutase appeared to be slightly lower in malignant cell lines in general as compared to normal tissues. The content of manganese superoxide dismutase was more variable than the content of the copper- and zinc-containing enzyme. Contrary to what has been suggested before, this enzyme did not appear to be generally lower in malignant cells compared to normal cells. One cell line, of mesothelioma origin (P27), was extremely abundant in manganese-containing superoxide dismutase; the concentration was almost an order of magnitude larger than in the richest normal tissue. Catalase was very variable both among the normal tissues and among the malignant cells, whereas glutathione peroxidase was more evenly distributed. In neither case was a general difference between normal cells and tissues and malignant cells apparent. The myocardial damage brought about by doxorubicin has been linked to toxic oxygen metabolites; particularly, an effect on the glutathione system has been noted. The heart is one of the tissues which have a low concentration of enzymes which protect against hydroperoxides. However, the deviation from other tissues is probably not large enough to provide a full explanation for the high doxorubicin susceptibility. In the present survey, no obvious relationship between generally assumed resistance to ionizing radiation or to radical-producing drugs and cellular content of any of the enzymes could be demonstrated.

Catalase↗
PubMed1981

CuZn-superoxide dismutase, Mn-superoxide dismutase, catalase and glutathione peroxidase in pancreatic islets and other tissues in the mouse.

Exogenous superoxide dismutase, catalase and scavengers of the hydroxyl radical protect pancreatic-islet cells against the toxic actions of alloxan in vitro [Grankvist et al. (1979) Biochem. J. 182, 17--25]. To test whether the extraordinary sensitivity of islet cells to alloxan is due to a deficiency of endogenous enzymes protecting against oxygen-reduction products, we assayed CuZn-superoxide dismutase, Mn-superoxide dismutase, catalase and glutathione peroxidase in mouse islets and other tissues. To correct for any blood contamination, haemoglobin was also measured in the tissue samples. Pancreatic islets were found to belong to tissues with relatively little activity of the protective enzymes. However, the deviation from other tissues in this respect is probably not large enough to explain the especially great susceptibility of islet cells to alloxan.

Alloxan↗
PubMed1981

Superoxide dismutase, catalase and glutathione peroxidase in infantile, late infantile and juvenile neuronal ceroid-lipofuscinosis.

The neuronal ceroid-lipofuscinoses are characterized by a widespread deposit in the body of pigments believed to be end products of lipid peroxidation damaged organelles. CuZn superoxide dismutase, Mn superoxide dismutase, catalase and glutathione peroxidase, enzymes which conceivably might protect against lipid peroxidation, were investigated in blood cells from patients afflicted with infantile, late infantile and juvenile neuronal ceroid-lipofuscinosis. In some cases the enzymic activities were slightly lower than the activities of the controls, but no deficiencies which might be of etiolgical importance were revealed.

Adolescent↗
PubMed1981

Copper- and zinc-containing superoxide dismutase and manganese-containing superoxide dismutase in human tissues and human malignant tumors.

Superoxide dismutases might conceivably protect against both ionizing radiation and free radical-producing antibiotic antitumor drugs. Copper- and zinc-containing superoxide dismutase (CuZn superoxide dismutase) and manganese-containing superoxide dismutase (Mn superoxide dismutase) were specifically assayed in human malignant tumors and for comparison in human tissues. The tumors possessed less CuZn superoxide dismutase than did the more metabolically active tissues, but there was a large overlap between the tissue and the tumor levels. Mn superoxide dismutase was found in all tumors, and the ratio between the activities of CuZn superoxide dismutase and Mn superoxide dismutase was not different from that of the normal tissues. Human tumors are thus different from tumors from other species which have been reported to be deficient or very low in Mn superoxide dismutase. There was no obvious relation between sensitivity to ionizing radiation and content of the enzymes among the tumors and the tissues, nor did tumor types known to be responsive to radical-producing drugs possess less CuZn superoxide dismutase or Mn superoxide dismutase than other tumors.

Adult↗
PubMedDate not supplied

Morphologic changes induced by short-term ischemia in the rat testis are not affected by treatment with superoxide dismutase and catalase.

Short-term testicular ischemia was induced unilaterally by ligating the testicular artery for 60 or 100 minutes in adult rats. After 7 days, the rats were fixed by vascular perfusion. The effect of ischemia and reperfusion was quantified using morphometric techniques. Occlusion of the testicular artery for 60 and 100 minutes resulted in a mild and moderate damage, respectively, to the seminiferous tubules. The contralateral control testis was not affected. To study the role of oxygen radicals in ischemia-reperfusion-induced testicular damage, rats were treated with superoxide dismutase and catalase. These radical scavengers did not influence the extent of testicular damage.

Animals↗
PubMedDate not supplied

A comparison of four assays detecting oxidizing species. Correlated reactivity of Fe(III)-quin2, but not Fe(III)-EDTA, with hydrogen peroxide.

Quin2, a fluorescent calcium probe, has a low affinity for calcium in comparison to its affinities for transition metal ions. Chelation of ferric ion with quin2 strongly enhanced the formation of oxidizing species in the presence of bolus H2O2 as detected with four assays, electron spin resonance with the spin-trap DMPO, the deoxyribose assay, the DMSO assay, and plasmid DNA strand breakage. In comparison, Fe(III)-EDTA reacted with bolus H2O2 only as detected with electron spin resonance and deoxyribose assay, but not as detected with the two latter assays. The addition of reductants, like ascorbate or superoxide generated by hypoxanthine/xanthine oxidase, to Fe(III)-EDTA in the presence of H2O2 produced plasmid DNA strand breakage and strong reactivity in both the DMSO and the deoxyribose assays. Our findings suggest that the main oxidizing species produced in Fenton-type reactions is hydroxyl radical. However, the reaction between Fe(III)-EDTA and bolus H2O2 appears to be exceptional and dominated by a nonhydroxyl radical species.

Aminoquinolines↗
PubMedDate not supplied

Superoxide dismutase isoenzymes in tissues and plasma from New Zealand black mice, nude mice and normal BALB/c mice.

In various types of autoimmune disease, an increased frequency of spontaneous chromosome breaks has been reported. Plasma from such patients induces chromosome breaks in normal cells. Exposure of plasma to superoxide radicals increases the breakage activity, and addition of superoxide dismutase protects against it. The New Zealand black mouse is an animal model of autoimmune disease which displays the breakage phenomenon. To test for the possibility that the breakage is related to deficient protection against superoxide radicals, the activities of superoxide dismutase isoenzymes were determined in tissues and blood from New Zealand black mice and compared with the activities of normal BALB/c mice. No differences between the strains were revealed in tissue EC-superoxide dismutase, CuZn superoxide dismutase and Mn superoxide dismutase activity. The erythrocyte superoxide dismutase activities were also equal. The plasma EC-superoxide dismutase activity was 35% lower in the New Zealand black mice than in the BALB/c mice. Between euthymic BALB/c mice and nude mice, previously reported to be deficient in tissue superoxide dismutase activity, no difference could be demonstrated.

Animals↗