Voltage-activated cation permeability in high-potassium but not low-potassium red blood cells.
We have recently reported that voltage-activated fluxes of Na, K, and Ca occur in human red blood cells [J.A. Halperin, C. Brugnara, M. Tosteson, T. Van Ha, and D. C. Tosteson. Am. J. Physiol. 257 (Cell Physiol. 26): C986-C996, 1989]. The cation permeability increases progressively as the membrane potential becomes more inside positive above +20 mV. In this paper we show that this effect also occurs in high-potassium (HK), but not in low-potassium (LK), sheep and dog red blood cells. This result suggests that the voltage-activated cation transport pathway is not the result of nonspecific dielectric breakdown of the lipid bilayer but, rather, relates to some membrane component, presumably a protein, that is expressed in HK human and sheep but not in LK sheep and dog red blood cells.
Halperin
J A
JA
Department of Cellular and Molecular Physiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115.
Brugnara
C
C
Van Ha
T
T
Tosteson
D C
DC
D000818:Animals; D002463:Cell Membrane Permeability; D004285:Dogs; D004910:Erythrocyte Membrane / Q000502:physiology*; D007473:Ion Channels / Q000502:physiology*; D008564:Membrane Potentials; D011188:Potassium / Q000097:blood*; D012756:Sheep; D012964:Sodium / Q000097:blood*
D007473:Ion Channels; D012964:Sodium; D011188:Potassium