English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The activity of the template-engaged form of RNA polymerase I from livers of adrenalectomized rats was about 50-60% of that of normal control rats, and increased about 2-fold at 6 h after the administration of dexamethasone. However, no change was found in the activity of the 'free' form of RNA polymerase I or the template-engaged form of RNA polymerase II. Immunochemical studies using guinea-pig anti-(RNA polymerase I) serum disclosed that the total number of RNA polymerase I molecules did not vary during the treatment with dexamethasone. Cycloheximide caused a rapid decrease in the template-engaged form of RNA polymerase I activity in normal rats and in dexamethasone-treated (6 h) adrenalectomized rats, to the value in adrenalectomized rats, but affected it only slightly in adrenalectomized rats. The elongation rate of rRNA-precursor synthesis in liver nuclei was not affected by a change in the concentration of circulating dexamethasone. From these results, it is concluded that about half the rRNA-precursor synthesis in rat liver is regulated by glucocorticoids, probably through the synthesis of short-lived protein(s) which may play a role in conversion of the 'dormant' form of RNA polymerase I into the 'engaged' form.

Effects of glucocorticoid and cycloheximide on the activity and amount of RNA polymerase I in nuclei of rat liver