Can isoflurane mimic ischaemic preconditioning in isolated rat heart?
Ischaemic preconditioning can protect the myocardium against ischaemic injury by opening of the adenosine triphosphate (ATP)-sensitive potassium (K(ATP)) channel. Isoflurane is also thought to open this channel. The present investigation tested the hypothesis that pre-ischaemic treatment with isoflurane mimics ischaemic preconditioning (producing chemical preconditioning) and thereby protects the myocardium against ischaemic injury in an isolated rat heart model. Control hearts underwent 30 min of global no-flow ischaemia followed by 60 min of reperfusion. The hearts of the preconditioning group underwent two 5 min periods of no-flow ischaemia interspersed with 5 min of reperfusion before the sustained ischaemia. In three additional groups, hearts were subjected to 15 min of 1.5 minimal alveolar concentration (MAC) of isoflurane (ISO-1), 15 min 3 MAC (ISO-2) or 25 min 1.5 MAC (ISO-3) of isoflurane followed by 5 min washout before the global ischaemia. Left ventricular (LV) developed pr