Effects of maleate on the content of CoA and its derivatives in rat kidney mitochondria

Effects of maleate on the content of CoA derivatives in isolated mitochondria and in the tissues of maleate-intoxicated rats have been studied. The addition of maleate to kidney mitochondria incubated with 2-oxo-glutarate decreased CoA-SH and acid-soluble acyl-CoA concentrations while acid insoluble acyl-CoA content remained unchanged. As a result, a substantial loss (depletion) of the total CoA occurred. Similar changes in CoA content were found in vivo in the kidneys of maleate-treated rats. Neither in the isolated liver mitochondria nor in the liver of intoxicated animals have such changes been observed before. Acetoacetate, the substrate for CoA transferase, added to kidney mitochondria before maleate, abolished its inhibitory effect on oxidation of 2-oxoglutarate and prevented the decrease of CoA content. The data are in accord with the previous findings indicating that maleate can bind and sequester CoA in the form of a stable and metabolically inert compound.