[Control of glutamate dehydrogenase activity in isolated rat liver mitochondria by purine nucleotides, cyclic AMP, alpha-ketoglutarate and phosphate].

Glutamate oxidation by mitochondria in the presence of arsenite and dinitrophenol is diminished by ADP, AMP, GDP and cyclic 3',5'-AMP. Mechanism of inhibition is noncompetitive and atractyloside-sensitive. Alpha-ketoglutarate is a more powerful inhibitor of glutamate oxidation. Inhibitions produced by alpha-ketoglutarate and nucleotide are not additive. Phosphate reverses inhibition of glutamate oxidation produced by nucleotides but only slightly that produced by alpha-ketoglutarate. It is concluded from the results obtained that GDH remains in intact mitochondria under effective control exerted by purine nucleotides (AMP, GDP, ADP, cAMP), alpha-ketoglutarate and phosphate, functioning mainly in the direction of reductive amination of alpha-ketoglutarate.