Effects of salicylate and γ-resorcylate on the metabolism of radioactive succinate and fumarate by rat-liver mitochondria and on dehydrogenase enzymes

Abstract

The effects of salicylate and gamma-resorcylate on the incorporation of C14 from [1,4-C142] succinate and [1,4-Cl42]fumarate into the soluble intermediates of rat-liver mitochondria were studied. In the absence of the drugs the mitochondria incorporated the isotope from the labelled succinate into fumarate, malate, citrate, asparate, glutamate and alanine. Salicylate and resorcylate increased the incorporation of C14 from the [1,4-C142]succinate into fumarate. malate and citrate but did not alter the utilization of the [1, 4-C142] fumarate. Resorcylate, but not salicylate, decreased the utilization of the radioactive succinate. Salicylate and resorcylate inhibited malate-dehydrogenase and isocitrate-dehydrogenase activities in vitro by competing with either NAD or NADP. Resorcylate, but no salicylate, inhibited succinate-dehydrogenase activity in vitro.