The enzymatic activity of the mitochondrial oligomycin-sensitive ATPase was investigated during isoproterenol-induced cell injury of myocardium, using rat heart homogenates and a potentiometric method. The enzymatic activity of the oligomycin-sensitive ATPase and the inhibitory action of oligomycin do not show significant alterations upon treatment with isoproterenol. These results are inconsistent with the hypothesis that modifications in the active configuration of the mitochondrial ATPase take place during isoproterenol-induced injury of myocardium.
