Uptake of chromate by rat thymocytes and role of glutathione in its cytoplasmic reduction.
1. Chromate is taken up by rat thymocytes over a wide range of extracellular chromate concentrations (0.074 +/- 5.0 mM). 2. Chromate uptake followed Michaelis-Menten kinetics and was inhibited by 4-acetamido-4'-isothiocyano-stilbene-2,2'-disulphonic acid, suggesting that the anion carrier was responsible for the uptake by rat thymocytes. 3. The decrease in chromate uptake by the thiol(SH)-blocking agent diethyl maleate, the increased chromate uptake caused by the thiol-protecting agent dithiothreitol, and the reduction of glutathione/glutathione disulphide ratio indicated that the maintenance of the integrity of SH-groups greatly influenced the uptake and reduction of Cr(VI), and that glutathione may be responsible for the intracellular reduction of Cr(VI) to Cr(III).
Department of Pharmacology, University of Padova, Italy.
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P
Debetto
P
P
Arslan
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M
Antolini
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Luciani
D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002478:Cells, Cultured; D002840:Chromates / Q000378:metabolism* / Q000494:pharmacology; D002860:Chromium Radioisotopes; D004229:Dithiothreitol / Q000494:pharmacology; D005978:Glutathione / Q000031:analogs & derivatives / Q000378:metabolism*; D019803:Glutathione Disulfide; D007700:Kinetics; D008298:Maleates / Q000494:pharmacology; D051381:Rats; D017670:Sodium Compounds; D013950:Thymus Gland / Q000187:drug effects / Q000378:metabolism*
D002840:Chromates; D002860:Chromium Radioisotopes; D008298:Maleates; D017670:Sodium Compounds; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; C028982:sodium chromate(VI); C014476:diethyl maleate; D005978:Glutathione; D004229:Dithiothreitol; D019803:Glutathione Disulfide