A classic paper by Murry, Richard, Reimer and Jennings published in 1990 in Circulation Research showed that preconditioning showed the rate of ATP breakdown during a subsequent sustained period of ischemia. The mechanism responsible for reduced ATP breakdown is still unknown, but perhaps it is related to inhibition of the F1-F0 ATPase. This is an attractive hypothesis given a number of recent studies suggesting that the F1-F0 ATPase can form the mitochondrial permeability transition pore.