BIOCHEMICAL MECHANISMS OF HORMONE ACTION

Abstract

Some recent hypotheses on the mode of action of hormones are reviewed. One concept, arising from experiments with artificially cleaved ribonuclease, namely that hormones may complete some proteins to form an active enzyme, is regarded as unlikely. Moreover, the idea that hormones act as "allosteric effectors" of enzymes is not well substantiated. A third hypothesis, i. e. that hormones may act as gene activators, is discussed at some length. Gene activation would lead to production of messenger-RNA and induced enzyme synthesis. For ecdysone, the moulting hormone of insects, every step of this reaction sequence has been demonstrated experimentally.