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The contribution of vascular endothelial xanthine dehydrogenase/oxidase to oxygen-mediated cell injury.
Arch Biochem Biophys. 1992 May 01; 294(2):695-702.AB

Abstract

The conversion of xanthine dehydrogenase (XDH) to xanthine oxidase (XO) and the reaction of XO-derived partially reduced oxygen species (PROS) have been suggested to be important in diverse mechanisms of tissue pathophysiology, including oxygen toxicity. Bovine aortic endothelial cells expressed variable amounts of XDH and XO activity in culture. Xanthine dehydrogenase plus xanthine oxidase specific activity increased in dividing cells, peaked after achieving confluency, and decreased in postconfluent cells. Exposure of BAEC to hyperoxia (95% O2; 5% CO2) for 0-48 h caused no change in cell protein or DNA when compared to normoxic controls. Cell XDH+XO activity decreased 98% after 48 h of 95% O2 exposure and decreased 68% after 48 h normoxia. During hyperoxia, the percentage of cell XDH+XO in the XO form increased to 100%, but was unchanged in air controls. Cell catalase activity was unaffected by hyperoxia and lactate dehydrogenase activity was minimally elevated. Hyperoxia resulted in enhanced cell detachment from monolayers, which increased 112% compared to controls. Release of DNA and preincorporated [8-14C]adenine was also used to assess hyperoxic cell injury and did not significantly change in exposed cells. Pretreatment of cells with allopurinol for 1 h inhibited XDH+XO activity 100%, which could be reversed after oxidation of cell lysates with potassium ferricyanide (K3Fe(CN)6). After 48 h of culture in air with allopurinol, cell XDH+XO activity was enhanced when assayed after reversal of inhibition with K3Fe(CN)6, and cell detachment was decreased. In contrast, allopurinol treatment of cells 1 h prior to and during 48 h of hyperoxic exposure did not reduce cell damage. After K3Fe(CN)6 oxidation, XDH+XO activity was undetectable in hyperoxic cell lysates. Thus, XO-derived PROS did not contribute to cell injury or inactivation of XDH+XO during hyperoxia. It is concluded that endogenous cell XO was not a significant source of reactive oxygen species during hyperoxia and contributes only minimally to net cell production of O2- and H2O2 during normoxia.

Authors+Show Affiliations

Department of Anesthesiology, University of Alabama, Birmingham 35233-6810.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

1567225

Citation

Panus, P C., et al. "The Contribution of Vascular Endothelial Xanthine Dehydrogenase/oxidase to Oxygen-mediated Cell Injury." Archives of Biochemistry and Biophysics, vol. 294, no. 2, 1992, pp. 695-702.
Panus PC, Wright SA, Chumley PH, et al. The contribution of vascular endothelial xanthine dehydrogenase/oxidase to oxygen-mediated cell injury. Arch Biochem Biophys. 1992;294(2):695-702.
Panus, P. C., Wright, S. A., Chumley, P. H., Radi, R., & Freeman, B. A. (1992). The contribution of vascular endothelial xanthine dehydrogenase/oxidase to oxygen-mediated cell injury. Archives of Biochemistry and Biophysics, 294(2), 695-702.
Panus PC, et al. The Contribution of Vascular Endothelial Xanthine Dehydrogenase/oxidase to Oxygen-mediated Cell Injury. Arch Biochem Biophys. 1992 May 1;294(2):695-702. PubMed PMID: 1567225.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The contribution of vascular endothelial xanthine dehydrogenase/oxidase to oxygen-mediated cell injury. AU - Panus,P C, AU - Wright,S A, AU - Chumley,P H, AU - Radi,R, AU - Freeman,B A, PY - 1992/5/1/pubmed PY - 1992/5/1/medline PY - 1992/5/1/entrez SP - 695 EP - 702 JF - Archives of biochemistry and biophysics JO - Arch Biochem Biophys VL - 294 IS - 2 N2 - The conversion of xanthine dehydrogenase (XDH) to xanthine oxidase (XO) and the reaction of XO-derived partially reduced oxygen species (PROS) have been suggested to be important in diverse mechanisms of tissue pathophysiology, including oxygen toxicity. Bovine aortic endothelial cells expressed variable amounts of XDH and XO activity in culture. Xanthine dehydrogenase plus xanthine oxidase specific activity increased in dividing cells, peaked after achieving confluency, and decreased in postconfluent cells. Exposure of BAEC to hyperoxia (95% O2; 5% CO2) for 0-48 h caused no change in cell protein or DNA when compared to normoxic controls. Cell XDH+XO activity decreased 98% after 48 h of 95% O2 exposure and decreased 68% after 48 h normoxia. During hyperoxia, the percentage of cell XDH+XO in the XO form increased to 100%, but was unchanged in air controls. Cell catalase activity was unaffected by hyperoxia and lactate dehydrogenase activity was minimally elevated. Hyperoxia resulted in enhanced cell detachment from monolayers, which increased 112% compared to controls. Release of DNA and preincorporated [8-14C]adenine was also used to assess hyperoxic cell injury and did not significantly change in exposed cells. Pretreatment of cells with allopurinol for 1 h inhibited XDH+XO activity 100%, which could be reversed after oxidation of cell lysates with potassium ferricyanide (K3Fe(CN)6). After 48 h of culture in air with allopurinol, cell XDH+XO activity was enhanced when assayed after reversal of inhibition with K3Fe(CN)6, and cell detachment was decreased. In contrast, allopurinol treatment of cells 1 h prior to and during 48 h of hyperoxic exposure did not reduce cell damage. After K3Fe(CN)6 oxidation, XDH+XO activity was undetectable in hyperoxic cell lysates. Thus, XO-derived PROS did not contribute to cell injury or inactivation of XDH+XO during hyperoxia. It is concluded that endogenous cell XO was not a significant source of reactive oxygen species during hyperoxia and contributes only minimally to net cell production of O2- and H2O2 during normoxia. SN - 0003-9861 UR - https://www.unboundmedicine.com/medline/citation/1567225/The_contribution_of_vascular_endothelial_xanthine_dehydrogenase/oxidase_to_oxygen_mediated_cell_injury_ L2 - https://linkinghub.elsevier.com/retrieve/pii/0003-9861(92)90743-G DB - PRIME DP - Unbound Medicine ER -