[Relationship between the nucleolar and karyoplasmic forms of RNA-polymerase in the nuclei of normal cells from different tissues and following hydrocortisone administration].

Correlation of the nucleolar and karyoplasmic forms of RNA-polymerase was studied in the cell nuclei of the brain, liver, kidneys and the spleen of rats under normal conditions and after hydrocortisone administration. Hydrocortisone was found to stimulate both the nucleolar and karyoplasmic RNA synthesis. In the nuclei of different tissues correlation of the nuclear and karyoplasmic forms of RNA-polymerase changed under the effect of the hormone unequally. Transcription stimulated by hydrocortisone, both the nucleolar and karyoplasmic was suppressed by actinomycin D. This indicated that, together with the activation of the enzyme forms, the hormone caused releasing the transcribed genom regions. The NAD-pyrophosphorylase activity of the nuclei, both under normal conditions and after hydrocortisone administration, was studied as well. Stimulation of the NAD-pyrophosphorylase activity occurred under the effect of the hormone in the cell nuclei of all the tissues under study; this stimulation was most pronounced in the nuclei of the spleen and of the kidneys. Nuclei characterized by a high RNA-polymerase activity also possessed an increased NAD-pyrophosphorylase activity.