Inhibition of Ehrlich ascites cell anion transport by 1-isothiocyanate-4-benzenesulfonic acid.
The effects of 1-isothiocyanate-4-benzene sulfonic acid on steady state Cl- and SO24(4 transport in Ehrlich mouse ascites tumor cells were investigated. At 10 mM, 1-isothiocyanate-4-benzenesulfonic acid reduced SO24(-) exchange by 94% but Cl- exchange was reduced by only 37%; Cl- exchange was not further inhibited by as much as 60 min of preincubation with 1-isothiocyanate-4-benzenesulfonic acid. Inhibition of Cl- exchange was completely reversible following 30-45 min of contact with 1-isothiocyanate-4-benzenesulfonic acid whereas under the same conditions, inhibition of SO24(-) exchange was irreversible. The effect o 1-isothiocyanate-4-benzenesulfonic acid on SO24(-) transport could be reversed, however, when exposure to 1-isothiocyanate-4-benzene-sulfonic acid lasted for only 2 min. In these respects the action of 1-isothiocyanate-4-benzenesulfonic acid resembles that of 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid and 4,4'-diisothiocyano-1,2-diphenylethane-2,2'-disulfonic acid; the results are compatible with separate membrane sites for Cl- and SO24(-) transport. The Ki for reversible inhibition of SO24(-) transport, determined from a Dixon plot, was 4.8 mM and the inhibition appeared to be non-competitive.
D000818:Animals; D001557:Benzenesulfonates / Q000494:pharmacology*; D001692:Biological Transport / Q000187:drug effects*; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism*; D017879:Isothiocyanates; D007700:Kinetics; D051379:Mice; D013329:Structure-Activity Relationship; D013431:Sulfates / Q000378:metabolism*; D013861:Thiocyanates / Q000494:pharmacology*
D001557:Benzenesulfonates; D002712:Chlorides; D017879:Isothiocyanates; D013431:Sulfates; D013861:Thiocyanates; C015308:4-isothiocyanatobenzenesulfonate