title: Deoxygenation-induced cation fluxes in sickle cells: II. Inhibition by stilbene disulfonates.
abstract: Deoxygenation-induced cation movements in sickle cells were inhibited 80% to 85% by the anion transport inhibitor, 4,4'-diisothiocyano-2,2'disulfostilbene (DIDS). Morphologic sickling was not altered by DIDS treatment, demonstrating that morphologic sickling was not sufficient to produce cation leaks in sickle cells. DIDS inhibition of deoxygenation-induced cation flux was not affected when l- replaced Cl-, indicating that conductive anion movements did not limit cation flux in deoxygenated cells treated with DIDS. Inhibition was irreversible after preincubation with DIDS at 37 degrees C for 20 minutes, and was not affected by the oxygenation state of cells at the time of drug exposure. Sulfate self-exchange was inhibited at lower DIDS concentrations than was deoxygenation-induced flux. Incubation of cells with DIDS at 4 degrees C produced progressive blockade of sulfate exchange, but did not alter deoxygenation-induced cation fluxes. Other stilbene disulfonates, including compounds incapable of covalent reactions, also inhibited deoxygenation-induced cation movements, although several other inhibitors of anion exchange did not. Dissociation of the inhibition of anion exchange and deoxygenation-induced cation flux indicates that the DIDS effect on deoxygenation-induced cation movements does not involve the well-characterized stilbene binding site of the anion exchanger. These data provide evidence for a membrane constituent on the external surface of oxygenated sickle cells capable of interacting with DIDS to prevent the increase in cation permeability associated with sickling.
authors.affiliation: Department of Pediatrics, University of Cincinnati, College of Medicine, OH.
authors.forename: C H
authors.initials: CH
authors.lastname: Joiner
mesh_terms: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives / Q000494:pharmacology*; D000755:Anemia, Sickle Cell / Q000097:blood* / Q000473:pathology; D000837:Anion Exchange Resins; D001557:Benzenesulfonates / Q000494:pharmacology; D002412:Cations / Q000378:metabolism* / Q000493:pharmacokinetics; D002463:Cell Membrane Permeability / Q000187:drug effects; D004913:Erythrocytes, Abnormal / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D006579:Heterozygote; D006801:Humans; D017879:Isothiocyanates; D010084:Oxidation-Reduction / Q000187:drug effects; D010693:Phloretin / Q000494:pharmacology; D013267:Stilbenes / Q000494:pharmacology*; D013861:Thiocyanates / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000837:Anion Exchange Resins; D001557:Benzenesulfonates; D002412:Cations; D017879:Isothiocyanates; D013267:Stilbenes; D013861:Thiocyanates; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; C015308:4-isothiocyanatobenzenesulfonate; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D010693:Phloretin