THE BIOENERGETIC CHARACTERISTICS OF MITOCHONDRIA OF THE RAT LIVER AT LOW BODY TEMPERATURES

Many of the pathological effects of hypothermia are directly or indirectly associated with changes in the functioning of mitochondria, the sensitive indicators of which are their bioenergetics characteristics. In this paper, the bioenergetic characteristics of isolated rat liver mitochondria in normal and hypothermia of different depths were investigated. Moderate (30 °C) hypothermia was found to significantly increase the respiratory rate of mitochondria. The deepening of the hypothermic state to 20 °C continues to stimulate respiration, however, increase in its rate becomes less pronounced relatively moderate hypothermia. In both moderate and deep hypothermia, the rate of oxidative phosphorylation is increased, and respiratory controls, P/O, and sensitivity to 2.4 DNP of mitochondrion are reduced. Many of these changes in mitochondrial respiratory parameters are more pronounced with moderate hypothermia. A comparative analysis of the bioenergetic characteristics of mitochondria obtained in the study of glutamate- and succinate-dependent res-piration suggests that the stimulation of mitochondrial respiration during hypothermia occurs mainly due to changes in the functioning of Complex I of the respiratory chain.