ATP-SENSITIVE POTASSIUM CHANNELS AND MYOCARDIAL PRECONDITIONING

The ATP-sensitive potassium channel (K-ATP) has been shown to serve an endogenous cardioprotective role in a number of experimental models o f myocardial stunning and infarction. More importantly, a majority of evidence has also been obtained which suggests that the K-ATP channel may be intimately involved in both triggering and maintaining the card ioprotection afforded by the phenomenon of ischemic preconditioning pa rticularly in large animal models such as dogs and pigs. Although the evidence for an involvement of K-ATP in ischemic pre-conditioning is e quivocal in smaller animal species such as rabbits and rats, activatio n of this channel by K-ATP channel openers produces cardioprotection i n all species studied. Whether this channel is an important mediator o f ischemic preconditioning in all animal species including man and the mechanism by which this cardioprotective effect is obtained await fur ther experimental studies. Nevertheless, the use of selective potassiu m channel openers to mimic preconditioning in selected clinical settin gs maybe a desirable future therapeutic goal.