Trans effect of cellular potassium and chloride on ouabain resistant rubidium potassium influx in low potassium sheep red bleed cells further evidence for asymmetry of potassium chloride cotransport
Delpire, E.; Lauf, P.K.
Pfluegers Archiv European Journal of Physiology 419(5): 540-542
1991
Accession: 007959193
The electroneutral K-Cl cotransport in low K+ (LK) sheep red blood cells is kinetically asymmetric and thermodynamically outward poised (Delpire and Lauf, 1991a). We have shown previously by trans-inhibition kinetics that Cl- binds prior to K+ to the outside configuration of the carrier. In the present study, we confirm that K+ and Cl- bind randomly to the cytoplasmic aspect of the transporter because K+ in the absence of Cl-, and Cl- in the absence of K+, trans-inhibit ouabain-resistant Rb+ (K+) influx in these cells. In contrast to the trans-inhibition pattern observed outside, neither K+ nor Cl- trans-inhibit K+(Rb+) influx in the presence of the cotransported ion, further supporting the assymetry of the K-Cl cotransporter.