Inhibitory effect of pyruvate on release of glutathione and swelling of rat heart mitochondria.

Pyruvate prevents the permeability transition of rat heart mitochondria induced by the system calcium ions + phosphate or by the dithiol reagent phenylarsenoxide and measured as swelling. Since swelling induced by the latter is relieved by the dithiol 2,3-dimercaptopropanol (BAL), it is inferred that the effect of pyruvate might be mediated by the reduction of lipoic acid. In isolated mitochondria, pyruvate also exerts a protective effect when calcium + phosphate-induced swelling is exacerbated by hypoxic conditions. These results agree with our previous observations that pyruvate markedly prevents the loss of cytosolic and mitochondrial glutathione after ischemia or ischemia followed by reperfusion.