[Effect of bicarbonate and insulin on energy metabolism in the mitochondria of rat liver].

Administration of physiologically low doses of bicarbonate into rats caused an inhibition of oxidative phosphorylation and a transitory decrease in ATP content in liver mitochondria; at the same time, concentrations of malate and glutamate were unaltered and those of pyruvate and phosphoenolpyruvate were decreased. Insulin removed the bicarbonate effect on mitochondrial functions but affected only slightly the distribution of metabolites. Bicarbonate appears to activate pyruvate carboxylase and to inhibit succinate dehydrogenase as well as the operation of tricarboxylic acid cycle due to accumulation of oxaloacetate. The effect of insulin mimics acceleration of decarboxylation reactions in mitochondria.