Mitochondria: a target for myocardial protection

The ischemic heart requires reperfusion using clinical interventions, such as coronary artery bypass graft surgery, in order to recover. Despite recen t developments in myocardial protection techniques, reperfusion damage stil l occurs, and significant morbidity remains a problem. Therefore, the searc h continues for techniques that will Limit myocardial damage and that will enhance recovery upon reperfusion. Mitochondria are known to be intimately involved in the processes that lead to cell death following reperfusion, in both necrotic and apoptotic forms of cell death, and so are potential targ ets for protective intervention. In this review, we consider several aspect s of mitochondrial function that we believe to be possible targets for myoc ardial protection; namely, mitochondrial Ca2- transport. the permeability t ransition pore, and improved mitochondrial substrate supply. We discuss wor k by ourselves and others in these areas, and also consider the recently pr oposed role of mitochondrial ATP-dependent K+ channels in mediating myocard ial protection by ischemic preconditioning. Finally, we describe use of car dioplegic solutions in the clinical setting, and discuss how improved under standing of the aspects of mitochondrial function summarised above may lead to better protective strategies in the future. (C) 2001 Elsevier Science I nc. All rights reserved.