Functional activity of mitochondria and generation of oxygen free radicalsafter prolonged myocardial ischemia: Effect of ischemic preconditioning

Effect of ischemic preconditioning on the rate of oxygen free radicals form ation, functional activity of mitochondria and restoration of cardiac contr actility after prolonged ischemia was studied on isolated Langendorff-perfu sed rat hearts. Restoration of contractile function occurred in 50% of cont rol hearts and in almost all hearts subjected to ischemic preconditioning ( 4 short cycles of ischemia and reperfusion). Mitochondria isolated from pre conditioned hearts significantly better maintained their functional activit y both after long-term ischemia and reperfusion. This was associated with s ignificantly diminished rate of oxygen free radicals generation.