[The importance of the substrate for the induction of tyrosine-alpha-ketoglutarate-transaminase in RLC-cells (author's transl)].

1. Dexamethasone phosphate causes approximately a threefold increase of the tyrosine-alpha-ketoglutarate transaminase in the culture of RLC cells. 2. The induction of the enzyme depends on the presence of L-tyrosine. Omission of L-leucine or L-tryptophan, respectively, has no effect. 3. Omission of L-tyrosine influences the activity of the lactate dehydrogenase and malate dehydrogenase not at all and that of the glucose-6-phosphate-dehydrogenase only to a small extent. 4. In the absense of L-tyrosine an superinduction takes also place by actinomycin.