RIBONUCLEIC ACID SYNTHESIS AND OESTRADIOL ACTION IN THE UTERUS

Abstract

ABSTRACT Some aspects of the fate of oestradiol in uterine cells and of a proposed »cascade« mechanism of its activity are discussed. After a newly described step of entry of the hormone into the target cells, oestradiol is recognized by an intracellular transfer receptor system delivering it selectively to specific Non Histone Chromatin (NHC) protein of very feable abundance, provoking in turn (in a still unknown manner) the transcription of one (or a very few) gene(s). The resulting mRNA(s) would have a short half life and code for Key Intermediary Protein (KIP)(s) (also of very short half life). The latter activates the synthesis of essential component(s) of the cellular machinery in particular rRNAs, which are implicated post-transcriptionally in the generalized protein synthesis and therefore promote the growth of the differentiated cells. The reported changes in uterine RNA polymerase activity and protein synthesis are also discussed in the frame of other mechanisms.