We studied the oxidative phosphorylation and the respiratory control of liver mitochondria in normal and alloxan diabetic rats. We obtained the following results.
1) Respiratory control index and ADP/O for alloxan diabetic liver mitochondria were found to be lower than that of control.
2) Low levels of respiratory control index and ADP/O for alloxan diabetic rats recovered to normal after injection of insulin, but did not rise by addition of insulin in vitro.
3) Insulin blocked the respiratory release by D. N. P. in mitochondria suspension of rats liver.