Effects of Whole-body X-irradiation on Nuclear RNA Polymerase Activities in Rat Tissues

抄録

1. Mg⁺⁺-dependent and Mn⁺⁺/(NH₄)₂SO₄-dependent RNA poly-merase [nucleosidetriphosphate: RNA nucleotidyltransferase, EC 2. 7. 7. 6] activities in liver-nuclei increased by about 40% over the respective controls 24 hr after whole-body X-irradiation (650 r) of intact, ad libitum fed rats, and then the activities turned to subcontrol levels during the 10 days postirradiation.
2. Similar changes in the activities of liver RNA polymerase were observed on irradiation for fasted rats but not for adrenalectomized animals.
3. The induction of RNA polymerase as well as of tyrosine trans-aminase [L-tyrosine: 2-oxoglutarate aminotransferase, EC 2. 6. 1. 5] by cortisol-administration was not influenced by X-irradiation.
4. The effects of X-irradiation on Mg⁺⁺-dependent and Mn⁺⁺/ (NH₄)₂SO₄-dependent RNA polymerase activities in testis, spleen and thymus of rats were also described.