title: The effect of oxygen radicals on rat thymocyte glucose transport is independent of the site of their generation.
abstract: We studied the relationship between the site of production of oxygen radicals and their effect on a rat thymocyte functional activity, the glucose transport, measured using a radioactive analogue of glucose, 2-deoxy-glucose. We compared the effects of a hydrophilic thermolabile azo compound, mimicking a radical attack outside the cell, with the lipid-soluble cumene hydroperoxide, which initiates lipid peroxidation in cell membranes. Our results show that a low grade oxidative stress stimulated glucose uptake rapidly, independently of the site of radical generation. In the presence of the azocompound, glucose uptake increased smoothly, attaining its maximum extent within 1 h. In thymocytes treated with cumene hydroperoxide the rate of glucose transport increased suddenly and remained constant over 1 h. The effects of the radical donors on TBARS production and protein sulfhydryl groups content were also evaluated. In thymocytes treated with the azo derivative no lipid peroxidation was observed, but a slow decrease of protein thiol groups occurred; after the addition of cumene hydroperoxide sulfhydryl groups did not change and TBARS increased significantly. The water-soluble antioxidant Trolox was able to remove the glucose uptake increase induced by the hydrophilic initiator and to delay the loss of membrane integrity.
authors.affiliation: Dipartimento di Biochimica G. Moruzzi, Università di Bologna, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Fiorentini
authors.forename: G
authors.initials: G
authors.lastname: Hakim
authors.forename: L
authors.initials: L
authors.lastname: Zambonin
authors.forename: L
authors.initials: L
authors.lastname: Landi
mesh_terms: D000578:Amidines / Q000494:pharmacology*; D000818:Animals; D001555:Benzene Derivatives / Q000494:pharmacology*; D001692:Biological Transport; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D003847:Deoxyglucose / Q000378:metabolism; D005609:Free Radicals / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism*; D007700:Kinetics; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress; D051381:Rats; D017208:Rats, Wistar; D013601:T-Lymphocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D013950:Thymus Gland / Q000166:cytology
chemical_list: D000578:Amidines; D001555:Benzene Derivatives; D005609:Free Radicals; D016877:Oxidants; D017392:Thiobarbituric Acid Reactive Substances; C046728:2,2'-azobis(2-amidinopropane); D003513:Cycloheximide; D003847:Deoxyglucose; D005947:Glucose; C007164:cumene hydroperoxide