Figure 2.

Diagram shows that cardioprotection of ischemic preconditioning (e.g. 3 bouts of ischemia (I) and reperfusion (R), each for 5 min, before a prolonged ischemia phase) and postconditioning (e.g., 6 cycles of I and R, each for 30 sec, at reperfusion) is associated with activation of the reperfusion injury salvage kinase (RISK) pathway. An important outcome relates to upregulation of phosphatidylinositol-3 kinase (PI3K)/Akt pathway which, in turn, leads to phosphorylation and inactivation of glycogen synthase kinase-3β (GSK-3β) culminating in inhibition of the mitochondrial permeability transition (MPT) pore. Also, shown is mitochondrial (mito.) K_ATP channels whose activation confers cardioprotection, likely through inhibition of MPT pore induction.