Tyrosine-α-Ketoglutarate Transaminase: Induction by Epinephrine and Adenosine-3′,5′-Cyclic Phosphate

Epinephrine and the N6-O2'-dibutyryl analog of adenosine-3', 5'-cyclic phosphate both are effective inducers of tyrosine-alpha-ketoglutarate transaminase in explants of fetal rat liver maintained in organ culture. Combinations of these inducers with each other and with hydrocortisone, another inducer, yielded results which suggest that cyclic adenylic acid is an intermediate in the induction by epinephrine and that the mechanism by which it induces is different from that by which hydrocortisone operates.