title: Effect of potential-dependent potassium uptake on production of reactive oxygen species in rat brain mitochondria.
abstract: The effect of potential-dependent potassium uptake on reactive oxygen species (ROS) generation in mitochondria of rat brain was studied. It was found that the effect of K+ uptake on ROS production in the brain mitochondria under steady-state conditions (state 4) was determined by potassium-dependent changes in the membrane potential of the mitochondria (ΔΨm). At K+ concentrations within the range of 0-120 mM, an increase in the initial rate of K(+)-uptake into the matrix resulted in a decrease in the steady-state rate of ROS generation due to the K(+)-induced depolarization of the mitochondrial membrane. The selective blockage of the ATP-dependent potassium channel (K(ATP)(+)-channel) by glibenclamide and 5-hydroxydecanoate resulted in an increase in ROS production due to the membrane repolarization caused by partial inhibition of the potential-dependent K+ uptake. The ATP-dependent transport of K+ was shown to be ~40% of the potential-dependent K+ uptake in the brain mitochondria. Based on the findings of the experiments, the potential-dependent transport of K+ was concluded to be a physiologically important regulator of ROS generation in the brain mitochondria and that the functional activity of the native K(ATP)(+)-channel in these organelles under physiological conditions can be an effective tool for preventing ROS overproduction in brain neurons.
authors: Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kiev, 01601, Ukraine. a-dubensky@mail.ru.
authors: O V
authors: OV
authors: Akopova
authors: L I
authors: LI
authors: Kolchinskaya
authors: V I
authors: VI
authors: Nosar
authors: V A
authors: VA
authors: Bouryi
authors: I N
authors: IN
authors: Mankovska
authors: V F
authors: VF
authors: Sagach
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D005905:Glyburide / Q000494:pharmacology; D007004:Hypoglycemic Agents / Q000494:pharmacology; D054086:KATP Channels / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D007004:Hypoglycemic Agents; D054086:KATP Channels; D017382:Reactive Oxygen Species; D011188:Potassium; D005905:Glyburide