Cellular localization of sulfobromophthalein transport activity in rat liver.
The movement of sulfobromophthalein is measured in rat liver plasma-membrane vesicles by direct dual-wavelength spectrophotometry. The technique is based on the principle that the dye, when entering a more acidic compartment, changes its absorption in the visible region. From this study it may be concluded that, among the different cellular subfractions, only liver plasma-membrane vesicles can catalyze electrogenic transport of sulfobromophthalein. Plasma membranes from erythrocytes are unable to perform such a function. The movement follows the distribution pattern of (Na+ + K+)-ATPase and it is therefore concluded that this process occurs exclusively at the sinusoidal membrane level. Inhibition studies confirm that the process is catalyzed by bilitranslocase.
D000818:Animals; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D002570:Ceruloplasmin; D004910:Erythrocyte Membrane / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism*; D008564:Membrane Potentials; D008565:Membrane Proteins / Q000502:physiology; D008862:Microsomes, Liver / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D000254:Sodium-Potassium-Exchanging ATPase / Q000032:analysis; D012995:Solubility; D013448:Sulfobromophthalein / Q000378:metabolism*; D014634:Valinomycin / Q000494:pharmacology
D008565:Membrane Proteins; D013448:Sulfobromophthalein; D014634:Valinomycin; D002570:Ceruloplasmin; C033838:bilitranslocase; D000254:Sodium-Potassium-Exchanging ATPase