Preconditioning and postconditioning: The essential role of the mitochondrial permeability transition pore

Objective The opening of the mitochondrial permeability transition pore (mPTP) at the time of myocardial reperfusion is a critical determinant of cell death. Emerging studies suggest that suppression of mPTP opening may underlie the cardioprotection elicited by both ischemic preconditioning (IPC) and postconditioning (IPost). To further evaluate the role of the mPTP in cardioprotection, we hypothesized that hearts deficient in cyclophilin-D (CYP-D−/−), a key component of the mPTP, will be resistant to cardioprotection conferred by ischemic and pharmacological preconditioning and postconditioning.