Influence of Hypophysectomy and of Adrenocorticotropic Hormone on a Mammalian Adaptive Enzyme System

Abstract

THE purification of a mammalian hepatic tryptophan peroxidase–oxidase system, and its properties, have been described by Knox and Mehler¹. These authors demonstrated the system to be an adaptive one, increasing five- to ten-fold within 4–10 hr. following the intraperitoneal injection of massive doses of L-tryptophan². That the adaptation is in fact real, with the increase in enzymatic activity resulting from a net synthesis of enzyme protein, has been discussed by Knox and Mehler², and also by Lee and Williams³, who employed ethionine to inhibit the adaptation synthesis.