On the mechanism of the glycogenolytic effect of dinitrophenol. Activity of phosphofructokinase in perfused hearts.

To explain the mechanism of DNP action the contents of ATP, ADP, AMP and G-6-P were determined in perfused rat hearts in a period of time in which the rate of the glycogenolysis was increased. The levels of these metabolytes in the extract were consistent with an increase of the phosphofructokinase activity. On the other hand, the finding of higher activity of phosphyrylase beta kinase in DNP-poisoned animals could be explained as due to the low content of G-6-P in the perfused hearts subjected to the action of the drug.