Effect of corticosteroids on tadpole hepatic transaminases

Abstract

Activities of aspartate-α-ketoglutarate (E.C.2.6.1.1), alanine-α-ketoglutarate (E.C.2.6.1.2) and tyrosine-α-ketoglutarate (E.C.2.6.1.5) transaminases in the livers of tadpoles were determined and the effect of corticoids and tyrosine upon the hepatic activities of these three transaminase studied. In contrast to mammalian livers, neither hydrocortisone nor tyrosine caused an appreciable increase in hepatic transaminase activities in tadpoles. The hepatic transaminase activities were not affected by treatment of the tadpoles with Metopirone, an inhibitor which blocks the biosynthesis of corticoids in vivo.