The mode of action of oestradiol. II. The synthesis of RNA.

Abstract 1. 1. The synthesis of RNA in immature rat uterus under the influence of oestradiol-17β has been measured during the first 8 h of hormone action. 2. 2. There is no increase in the uterine RNA content, as measured by chemical methods, over the first 7 h. 3. 3. When the effect of oestradiol on the transport of RNA precursor into the uterus is eliminated there is no significant increase in the amount of precursor incorporated into RNA until at least 5 h after administration of oestradiol. 4. 4. The pattern of RNA synthesis 6 h after hormone treatment shows greatly increased incorporation of precursors into rRNA and tRNA but only a small increase in the DNA-like RNA fraction.