title: Oxaloacetate uptake into rat brain mitochondria and reconstruction of the malate/oxaloacetate shuttle.
abstract: Reconstruction, using non-synaptosomal rat brain mitochondria, has been made here of the malate/oxaloacetate shuttle, made possible by the occurrence in rat brain mitochondria of a carrier mediated transport for oxaloacetate (Km = 60 microM), sensitive to dicarboxylate analogues and mersalyl, and of the two isoenzymes of malate dehydrogenase. Malate/oxaloacetate shuttle shows a high affinity for malate (Km = 100 microM) and Vmax = 40 nmoles NADH oxidized/min X mg mitochondrial protein at 20 degrees C. Its rate appears to depend on the activity of the malate/oxaloacetate exchange across the mitochondrial membrane. A possible role for the oxaloacetate carrier is proposed in aminoacid brain metabolism.
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D001921:Brain / Q000378:metabolism*; D007700:Kinetics; D008293:Malates / Q000378:metabolism*; D008634:Mersalyl / Q000494:pharmacology; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D010071:Oxaloacetates / Q000378:metabolism*; D010084:Oxidation-Reduction; D051381:Rats
chemical_list: D008293:Malates; D010071:Oxaloacetates; D008634:Mersalyl; C030298:malic acid