Summary
Rapid uptake of Ba2+ by respiring rat liver mitochondria is accompanied by a transient stimulation of respiration. Following accumulation of Ba2+, e.g. at a concentration of 120 nmol per mg protein, the mitochondria exhibit reduced rates of state 3 and uncoupler-stimulated respiration. ADP-stimulated respiration is inhibited at a lower concentration of Ba2+ than is required to affect uncoupler-stimulated respiration, suggesting a distinct effect of Ba2+ on mechanisms involved in synthesis of ATP. Ba2+, which has an ionic radius similar to that of K+, inhibits unidirectional K+ flux into respiring rat liver mitochondria. This effect on K+ influx is observable at concentrations of Ba2+, e.g. 23 to 37 nmol per mg protein, which cause no significant change in state 4 or uncoupler-stimulated respiration. The accumulated Ba2+ decreases the measuredV max of K+ influx, while having little effect on the apparentK m for K+. The inhibition of K+ influx by Ba2+ is seen in the presence and absence of mersalyl, an activator of K+ influx. In contrast, under the conditions studied, Ba2+ has no apparent effet on the rate of unidirectional K+ efflux. These data are consistent with the idea that K+ may enter and leave mitochondria via spearate mechanisms.
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Armstrong, C.M., Taylor, S.R. 1980. Interaction of barium ions with potassium channels in squid giant axons.Biophys. J. 30:473–488
Azzone, G.F., Bortolotto, F., Zanotti, A. 1978. Induction of electroneutral exchanges of H+ with K+ in rat liver mitochondria.FEBS Lett. 96:135–140
Bernardi, P., Azzone, G.F. 1983. Electroneutral H+/K+ exchange in liver mitochondria.Biochim. Biophys. Acta 724:212–223
Bogucka, K., Wojtczak, L. 1979. On the mechanism of mercurial-induced permeability of the mitochondrial membrane to K+.FEBS Lett. 100:301–304
Brierley, G.P., Knight, V.A., Settlemire, C.T. 1968. Ion transport by heart mitochondria. XII. Activation of monovalent cation uptake by sulfhydryl group reagents.J. Biol. Chem. 243:5035–5043
Chavez, E., Jung, D.W., Brierley, G.P. 1977. Energy-dependent exchange of K+ in heart mitochondria. K+ efflux.Arch. Biochem. Biophys. 183:460–470
Diwan, J.J. 1981. Dependence of mitochondrial K+ flux on pH.Biochem. Soc. Trans. 9:153–154
Diwan, J.J., Aronson, D., Gonsalves, N.O. 1980. Effect of mersalyl on mitochondrial K+ flux.J. Bioenerg. Biomembr. 12:205–212
Diwan, J.J., Dazé, M., Richardson, R., Aronson, D. 1979. Kinetics of Mg2+ flux into rat liver mitochondria.Biochemistry 18:2590–2595
Diwan, J.J., DeLucia, A., Rose, P.E. 1983. Interacting effects of dibutylchloromethyltin chloride, 2,3-dimercaptopropanol, and other reagents on mitochondrial respiration and K+ flux.J. Bioenerg. Biomembr. 15:277–288
Diwan, J.J., Lehrer, P.H. 1977. Inhibition of mitochondrial potassium ion flux by thallous ions.Biochem. Soc. Trans. 5:203–205
Diwan, J.J., Lehrer, P.H. 1978. Effects on mitochondrial K flux of pH, K concentration, andN-ethyl maleimide.Membr. Biochem. 1:43–60
Diwan, J.J., Markoff, M., Lehrer, P.H. 1977. Comparison of effects of mersalyl &N-ethyl maleimide on mitochondrial K+ flux.Indian J. Biochem. Biophys. 14:342–346
Diwan, J.J., Tedeschi, H., 1975. K+ fluxes and the mitochondrial membrane potential.FEBS Lett. 60:176–179
Eaton, D.C., Brodwick, M.S. 1980. Effects of barium on the potassium conductance of squid axon.J. Gen. Physiol. 75:727–750
Gamble, J.L. 1957. Potassium binding and oxidative phosphorylation in mitochondria and mitochondrial fragments.J. Biol. Chem. 228:955–971
Garlid, K.D. 1980. On the mechanism of regulation of the mitochondrial K+/H+ exchanger.J. Biol. Chem. 255:11273–11279
Harris, E.J., VanDam, K. 1968. Changes of total water and sucrose space accompanying induced ion uptake or phosphate swelling of rat liver mitochondria.Biochem. J. 106:759–766
Jung, D.W., Chavez, E., Brierley, G.P. 1977. Energy-dependent exchange of K+ in heart mitochondria. K+ influx.Arch. Biochem. Biophys. 183:452–459
Jung, D.W., Shi, G.-Y., Brierley, G.P. 1981. Induction of passive monovalent cation-exchange activity in heart mitochondria by depletion of endogenous divalent cations.Arch. Biochem. Biophys. 209:356–361
Latorre, R., Miller, C. 1983. Conduction and selectivity in potassium channels.J. Membrane Biol. 71:11–30
Layne, E. 1957. Spectrophotometric and turbidometric methods for measuring proteins.Methods Enzymol. 3:447–454
Martin, W.H., Beavis, A.D., Garlid, K.D. 1984. Identification of an 82,000-dalton protein responsible for K+/H+ antiport in rat liver mitochondria.J. Biol. Chem. 259:2062–2065
Mitchell, P. 1961. Coupling of phosphorylation to electron and hydrogen transfer by a chemiosmotic mechanism.Nature (London) 191:144–148
Mitchell, P., Moyle, J. 1969. Translocation of some anions, cations and acids in rat liver mitochondria.Eur J. Biochem. 9:149–155
Nakashima, R.A., Dordick, R.S., Garlid, K.D. 1982. On the relative roles of Ca2+ and Mg2+ in regulating the endogenous K+/H+ exchanger of rat liver mitochondria.J. Biol. Chem. 257:12540–12545
Rasheed, B.K.A., Diwan, J.J., Sanadi, R. 1984. Activation of potassium ion transport in mitochondria by cadmium ion.Eur. J. Biochem. 144:643–647
Sanadi, D.R., Hughes, J.B., Joshi, S. 1981. Activation of potassium-dependent H+ efflux from mitochondria by cadmium and phenylarsine oxide.J. Bioenerg. Biomembr 13:425–431
Saris, N.-E., Åkerman, K.E.O. 1980. Uptake and release of bivalent cations in mitochondria.In: Current Topics in Bioenergetics. D.R. Sanadi, editor. Vol. 10, pp. 103–179. Academic, New York
Skulskii, I.A., Saris, N.-E.L., Glasunov, V.V. 1983. The effect of the energy state of mitochondria on the kinetics of unidirectional cation fluxes.Arch. Biochem. Biophys. 226:337–346
Srivastava, J., Diwan, J.J. 1983. Effect of phenylarsine oxide on mitochondrial K+ flux.Biophys. J. 41:139a
Vainio, H., Mela, L., Chance, B. 1970. Energy dependent bivalent cation translocation in rat liver mitochondria.Eur. J. Biochem. 12:387–391
Zeiske, W., Van Driessche, W. 1983. The interaction of “K+-like” cations with the apical K+ channel in frog skin.J. Membrane Biol. 76:57–72
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Diwan, J.J. Ba2+ uptake and the inhibition by Ba2+ of K+ flux into rat liver mitochondria. J. Membrain Biol. 84, 165–171 (1985). https://doi.org/10.1007/BF01872214
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DOI: https://doi.org/10.1007/BF01872214