Optimizing the oxygen balance during initial reperfusion with 2,3-butanedione monoxime attenuates cardiac reperfusion injury.

The effect of 20 mmol/L butanedione monoxime on myocardial ischemia/reperfusion damage was studied in isolated guinea pig hearts. Three groups of hearts (n = 8) were perfused in the Langendorff mode and cardioplegic arrest was induced with St. Thomas Hospital II solution (STS) at 37 degrees C for 50 min. Myocardial oxygen demand, recovery of myocardial function, and creatine kinase release during 30 min of reperfusion were monitored. Preservation of myocardial ultrastructure was determined by electron microscopy. Control (C) hearts underwent cardioplegic arrest and reperfusion without treatment. BDM was added during cardioplegic arrest in BDMSTS hearts, or to the initial (20 min) reperfusate in BDMREP hearts. BDM during initial reperfusion markedly reduced O2 demand and prevented creatine kinase release from cardiac myocytes, resulting in improved recovery of myocardial function and attenuation of myocardial ultrastructural damage after washout of the drug. In contrast, addition of BDM to the cardioplegic solution provided no protection from ischemic or reperfusion injury.