O. V. Akopova, V. I. Nosar, L. I. Kolchinskaya, I. N. Mankovska, M. K. Malysheva, V. F. Sagach
The effect of potential-dependent potassium uptake on the transmembrane potential difference (??m) in rat brain mitochondria has been studied. It was shown that in potassium concentration range of 0-120 mM the potential-dependent K+-uptake into matrix leads to the increase in respiration rate and mitochondrial depolarization. ATP-dependent potassium channel (K+ATP-channel) blockers, glibenclamide and 5-hydroxydecanoate, block ~35% of potential-dependent potassium uptake in the brain mitochondria. It was shown that K+ATP-channel blockage results in membrane repolarization by ~20% of control, which is consistent with experimental dependence of ??m on the rate of potential-dependent potassium uptake. Obtained experimental data give the evidence that functional activity of K+ATP-channel is physiologically important in the regulation of membrane potential and energy-dependent processes in brain mitochondria.
Key words: K+, transport, K+ATP-channel, membrane potential, oxygen consumption, brain mitochondria.
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