Energy-dependent efflux of K+ from heart mitochondria
Por:
Chavez E., Jung D.W., Brierley G.P.
Publicada:
1 ene 1977
Resumen:
The efflux of 42K+ from the matrix of isolated heart mitochondria under conditions of steady state K+ has the properties of an energy-linked K+ K+ exchange reaction. Efflux requires respiration and external K+, is sensitive to uncouplers and to Mg+2, and is markedly decreased by oxidative phosphorylation. Efflux is stimulated by Pi and by mersalyl, but declines under conditions which promote net uptake of K+ and acetate. Acetate strongly inhibits efflux in the presence of mersalyl. These data suggest that mitochondrial K+ levels are not maintained by a balance between inward K+ pumping and a passive outward leak, but rather that a nearly constant K+ pool results from a regulated interplay between an inward K+ uniport (responsive to membrane potential) and a K+ H+ exchanger (responsive to the transmembrane pH gradient). © 1977.
Filiaciones:
Chavez E.:
Department of Physiological Chemistry, Ohio State University Columbus, OH 43210, United States
Jung D.W.:
Department of Physiological Chemistry, Ohio State University Columbus, OH 43210, United States
Brierley G.P.:
Department of Physiological Chemistry, Ohio State University Columbus, OH 43210, United States
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