Permeability of bicarbonate to red cell ghost calculated from irreversible DIDS inhibited bicarbonate efflux

Value 1.7E-06 cm/sec
Organism Human Homo sapiens
Reference Gasbjerg PK, Knauf PA, Brahm J. Kinetics of bicarbonate transport in human red blood cell membranes at body temperature. J Gen Physiol. 1996 Dec108(6):565-75. p.570 right column bottom paragraphPubMed ID8972394
Method "On the basis of studies of chloride transport mainly at 0°C, the "ping-pong model" for anion exchange was proposed (Gunn and Frohlich, 1979 Frohlich and Gunn, 1986). According to this model, a transport site in the protein, unloaded or loaded with an anion, may either face the internal or the external compartment."
Comments "The permeability calculated from the irreversible-DIDS-inhibited bicarbonate efflux (Fig.2) is 1.7×10^-6 cm/sec at pH 7.8, almost twice as high as the permeability for irreversible DIDS-inhibited chloride efflux from intact red blood cells (P=1.0×10^-6 cm/sec, Gasbjerg et al., 1993). When DIDS-treated resealed red cell ghosts (irreversible inhibition) were suspended in media with up to 200µM DIDS (reversible inhibition, cf. Fig.2), the apparent permeability was reduced to 1.2×10^-6cm/sec." DIDS=4,4'-diisothiocyanostilbene-2,2'-disulfonic acid
Entered by Uri M
ID 110731