[Variations in ATP synthetase activity of rat liver mitochondria during aging and under the effect of thyroxine].

Experiments with 1-, 3-, 12- and 24-month male rats show a decrease in the rate of ATP synthesis by the liver mitochondria with oxidation of succinate and alpha-glycerophosphate. Administration of thyroxin to animals for 2 and 9 days evokes a more pronounced increase of ATP-synthetase activity in 12- and 24-month rats and an essential decrease of the age differences of the activity. It is suggested that the character of observed variations is caused by age changes in the system of the hormonal metabolism control.