[Energy status of rat liver during the dynamics of cold adaptation]

The energy state of rat liver at various times of cold acclimation has been studied. On day 10 of cold exposure, the energy state of the liver is characterized by a low level of ATP and the adenine nucleotide pool as well as by low values of the phosphorylation potential and the "energy charge". The respiratory control is decreased, while the low permeability of the inner mitochondrial membrane is increased. It is supposed that on days 10-15 after cold exposure the liver becomes actively involved in thermal stabilization. Cold acclimation on days 35-42 leads to an increase in State 3 respiration rate, respiratory control and energization of liver mitochondria. This allows to maintain the ATP level and the total adenine nucleotide pool in liver tissues at the control level. However, this does not seem to compensate completely for the energy expenditure because the phosphorylation potential and the "energy charge" of the liver are thereby decreased.