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.
Department of Cellular and Molecular Physiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115.
J A
JA
Halperin
C
C
Brugnara
T
T
Van Ha
D C
DC
Tosteson
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