Normothermic transfer times up to 3 min will not precondition the isolated rat heart.

Isolated, perfused heart preparations suffer an inevitable peri-operative delay (POD) before retrograde perfusion restores coronary flow. By varying this ischaemic period we investigated the threshold of POD-induced inadvertent preconditioning (PC) in the rat heart. Hearts subjected to POD at 37 degrees C increasing from 1, 2, 3, 5, 10 up to 15 min prior to 20 min retrograde perfusion were further subjected to 30 min global, normothermic ischaemia and 30 min reperfusion (index I/R).