Furosemide inhibition of chloride transport in human red blood cells.
The chloride self-exchange flux across the human red cell membrane is rapidly and reversibly inhibited by 10(-4) M furosemide, a potent chloruretic agent. Furosemide reduces the chloride flux at all chloride concentrations and increases the cellular chloride concentration at which the flux is half-maximum. Kinetic analysis of the flux measurements made at several furosemide and chloride concentrations yields a pattern of mixed inhibition with a dissociation constant for the inhibitor-transport mechanism complex of 5 X 10(-5) M. From this pattern of inhibition and other observations, including that the percent inhibition is independent of pH (range 5.6-8.9), we conclude that the anionic form of furosemide interacts primarily with the chloride transport mechanism at a site separate from both the transport site and the halide-reactive modifier site.
D001665:Binding Sites / Q000187:drug effects; D001667:Binding, Competitive; D001693:Biological Transport, Active / Q000187:drug effects; D002712:Chlorides / Q000378:metabolism*; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D005665:Furosemide / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics
D002712:Chlorides; D005665:Furosemide