The burst in ATP synthesis observed on addition of ADP to mitochondria

Abstract

• 1.

  1. Evidence is presented showing that the burst in ATP synthesis, occuring on addition of ADp to rat-liver mitochondria supplemented with β-hydroxybutyrate and phosphate, is due to the oxidation of endogenous NADH and not to a “discharg” of high-energy intermediates of oxidative phosphorylation.

• 2.

  2. The ATP burst is about 3 times the amount of NAD⁺ formed on the addition of ADP.

• 3.

  3. Accompanying the ATP burst and the oxidation of endogenous NADH there is an extra oxygen uptake equivalent to the oxidation of the NADH.

• 4.

  4. The ATP burst was abolished by 15 μM dinitrophenol.

• 5.

  5. With succinate as substrate, the ATP burst equalled the amount of NADH oxidized, indicating that reducing equivalents from NADH compete for the respiration chain with those coming from succinate.