Trans effects of cellular K and Cl on ouabain-resistant Rb(K) influx in low K sheep red blood cells: further evidence for asymmetry of K-Cl cotransport [corrected].
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 asymmetry of the K-Cl cotransporter.
Delpire
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E
Department of Physiology and Biophysics, Wright State University, School of Medicine, Dayton, Ohio 45401-0927.
Lauf
P K
PK
D000818:Animals; D001692:Biological Transport; D002712:Chlorides / Q000378:metabolism*; D004351:Drug Resistance; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D012413:Rubidium / Q000378:metabolism*; D012756:Sheep
D002712:Chlorides; D010042:Ouabain; D012413:Rubidium; D011188:Potassium