[Age-related changes in the functioning of the mitochondrial potassium-transporting system].

Changes in the rate of respiration and functioning of the ATP-dependent potassium channel the liver and heart mitochondria of one-, three-, eight-, and twenty four-month-old Wistar male rats have been investigated. It was shown that the activity of the channel in the mitochondria of both tissues in 24-months-old animals decreases more than three times, and the content of potassium, 1.5-2 times compared with young one-month-old rats. The changes occur against the background of age-related decrease of energy supply in mitochondria, the respiratory complex-I underganig the greatest changes upon aging. The decrease of channel activity may be the result of changes in channel sensitivity to modulators and a decrease in the expression of mitochondrial K(+)-transporting channel-protein with a molecular mass of 5.5 kDa upon aging found in this work. As a result, the functioning of not only the mitoK(ATP) but also the whole mitochondrial potassium cycle is impaired.