Effect of oestradiol on RNA polymerase of foetal guinea-pig uterus.

The administration of 10 micrograms oestradiol to the foetus of the guinea-pig (55-65 days of gestation) causes an increase in RNA polymerase I and II activities in the nuclei of the foetal uterus. RNA polymerase I activity increased by 4 times above the control values after 120 min (p less than 0.001) whereas RNA polymerase II activity increased more rapidly, reaching 2.5 times the control levels at 30 min and 4 times by 120 min after treatment (p less than 0.01).