Metabolic effects of substrates on the isolated guinea-pig heart in relation to arrhythmias during reperfusion

Abstract

Mechanisms whereby glucose reduces the incidence of pyruvate induced reperfusion arrhythmias in isolated guinea-pig hearts have been investigated. Alterations in cytoplasmic ATP/ADP ratios, creatine phosphate and glycogen were excluded as possible mechanisms. Likewise, data are presented that appear to be at variance with the proposition that glycolytically derived ATP may play a special role in the maintenance of electrical stability. To explain the anti-arrhythmic effects of glucose in terms of this thesis it is necessary to invoke compartmentation of glycolysis. A correlation between the incidence of arrhythmias and glycolytic ATP production can only exist if the contributions to glycolytic flux from glucose and glycogen utilisation can be regarded as separate.