Myocardial metabolic markers of total ischemia in vitro.

The influence of total ischemia on the formation of products of anaerobic metabolism was investigated in canine hearts in vitro. Contents of organic acids were quantitatively analyzed by gas chromatography-mass spectrometry, and high energy phosphate compounds were determined using the luciferin-luciferase enzyme system. During a 10-min period of total ischemia, myocardial creatine phosphate significantly decreased, while ATP remained unchanged as compared with preischemic values. Both 10 min and 60 min of ischemia induced significant increase in tissue succinic acid levels. In contrast, a significant increase in myocardial lactic acid content was only induced with 60 min of ischemia. The data obtained indicate that the accumulation of succinic acid may be regarded as a potential metabolic marker of myocardial total ischemia.