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Enhancement of erythrocyte superoxide dismutase activity: effects on cellular oxidant defense.
Blood 1989; 74(7):2542-9Blood

Abstract

To delineate further the role of superoxide dismutase (SOD) in red blood cell (RBC) oxidant defense, normal human erythrocytes were osmotically lysed and resealed in the presence of varying concentrations of exogenous SOD. This resulted in a dose-dependent increase in SOD activity in the resealed erythrocytes while maintaining nearly normal RBC hemoglobin concentration (less than 10% decrease from the control value), cell volume, and cellular deformability. Surprisingly, a five- or ninefold increase in SOD activity yielded no additional protection against superoxide-generating drugs (phenazine methosulfate or menadione sodium bisulfite). No significant differences were observed between the control and SOD-loaded RBCs in O2-driven methemoglobin formation or generation of thiobarbituric acid-reactive substances. In contrast, RBCs with elevated SOD activity pretreated with sodium azide (to block catalase activity) or 1-chloro-2,4-dinitrobenzene (to deplete reduced glutathione, GSH) showed significantly enhanced methemoglobin generation in response to superoxide generating drugs. No differential response was noted between the control, control-resealed, and SOD-loaded RBCs to oxidants other than superoxide. Based on our results and other data, we conclude that elevated SOD activity may imbalance cellular oxidant defense, resulting in enhanced oxidation due to the accelerated generation of H2O2, the product of O2- dismutation. This effect is significantly exacerbated under conditions in which H2O2 catabolism is altered.

Authors+Show Affiliations

Children's Hospital Oakland Research Institute, CA 94609.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

2553167

Citation

Scott, M D., et al. "Enhancement of Erythrocyte Superoxide Dismutase Activity: Effects On Cellular Oxidant Defense." Blood, vol. 74, no. 7, 1989, pp. 2542-9.
Scott MD, Eaton JW, Kuypers FA, et al. Enhancement of erythrocyte superoxide dismutase activity: effects on cellular oxidant defense. Blood. 1989;74(7):2542-9.
Scott, M. D., Eaton, J. W., Kuypers, F. A., Chiu, D. T., & Lubin, B. H. (1989). Enhancement of erythrocyte superoxide dismutase activity: effects on cellular oxidant defense. Blood, 74(7), pp. 2542-9.
Scott MD, et al. Enhancement of Erythrocyte Superoxide Dismutase Activity: Effects On Cellular Oxidant Defense. Blood. 1989 Nov 15;74(7):2542-9. PubMed PMID: 2553167.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Enhancement of erythrocyte superoxide dismutase activity: effects on cellular oxidant defense. AU - Scott,M D, AU - Eaton,J W, AU - Kuypers,F A, AU - Chiu,D T, AU - Lubin,B H, PY - 1989/11/15/pubmed PY - 1989/11/15/medline PY - 1989/11/15/entrez SP - 2542 EP - 9 JF - Blood JO - Blood VL - 74 IS - 7 N2 - To delineate further the role of superoxide dismutase (SOD) in red blood cell (RBC) oxidant defense, normal human erythrocytes were osmotically lysed and resealed in the presence of varying concentrations of exogenous SOD. This resulted in a dose-dependent increase in SOD activity in the resealed erythrocytes while maintaining nearly normal RBC hemoglobin concentration (less than 10% decrease from the control value), cell volume, and cellular deformability. Surprisingly, a five- or ninefold increase in SOD activity yielded no additional protection against superoxide-generating drugs (phenazine methosulfate or menadione sodium bisulfite). No significant differences were observed between the control and SOD-loaded RBCs in O2-driven methemoglobin formation or generation of thiobarbituric acid-reactive substances. In contrast, RBCs with elevated SOD activity pretreated with sodium azide (to block catalase activity) or 1-chloro-2,4-dinitrobenzene (to deplete reduced glutathione, GSH) showed significantly enhanced methemoglobin generation in response to superoxide generating drugs. No differential response was noted between the control, control-resealed, and SOD-loaded RBCs to oxidants other than superoxide. Based on our results and other data, we conclude that elevated SOD activity may imbalance cellular oxidant defense, resulting in enhanced oxidation due to the accelerated generation of H2O2, the product of O2- dismutation. This effect is significantly exacerbated under conditions in which H2O2 catabolism is altered. SN - 0006-4971 UR - https://www.unboundmedicine.com/medline/citation/2553167/Enhancement_of_erythrocyte_superoxide_dismutase_activity:_effects_on_cellular_oxidant_defense_ L2 - http://www.bloodjournal.org/cgi/pmidlookup?view=long&pmid=2553167 DB - PRIME DP - Unbound Medicine ER -