Correlation between myocardial blood flow and tissue succinate during acute ischemia

This study was performed to clarify the relationship between degree plus duration of myocardial ischemia and tissue succinate or lactate contents, and to assess whether their accumulation might be a metabolic marker of ischemic myocardium. Regional myocardial blood flow (MBF) was measured using the hydrogen gas clearance method in anesthetized open-chest dogs subjected to 10 min or 60 min of myocardial ischemia by coronary ligation. The contents of succinic acid and lactic acid in myocardium corresponding to locations of MBF measurement were quantitatively analyzed by gas chromatography-mass spectrometry. In severely ischemic areas with MBF less than 20 ml/min/100g, significant increases in both succinic and lactic acids were observed 10 min after coronary occlusion. Sixty min of ischemia induced significant increase in the myocardial succinic acid content not only in severely but also in moderately ischemic areas. In contrast, lactic acid was significantly increased only in the severely ischemic area 60 min after coronary occlusion. These results indicate a good correlation between degree plus duration of myocardial ischemia and tissue succinic acid content, suggesting that its accumulation in myocardium may be a reliable and sensitive metabolic marker of coronary ligation ischemia.