Insulin protects PDK1fl/+ and PDK1fl/− cells against hypoxia, while wortmannin abolishes any difference between PDK1fl/+ and PDK1fl/− cells in the effect of preconditioning. Original images of cardiomyocytes loaded with JC-1 under depicted conditions. Each frame in each row corresponds to 0 min, 30 min, 60 min, and 90 min, respectively. Graphs on the right show time course of diameter ratio or JC-1 ratio (essentially the same result have been obtained in two more independent experiments).