[Effects of cycloheximide and chlorotetracycline on the activities of RNA-polymerases in mouse liver nuclei].

: The activities of RNA-polymerases I and II in mouse liver nuclei isolated after injection of various poisons to mice were studied. An increased activity of RNA-polymerase I in the nuclei isolated from mouse liver after injection of the inhibitors of translation, i.e. cycloheximide and chlorotetracycline, was found. The activity of RNA-polymerase II remained unchanged. The inhibition of protein synthesis in mitochondria following the injection of chloramphenicol did not affect the activities of nuclear RNA-polymerases. The animal poisoning by carbon tetrachloride accompanied by a total decrease of the rates of protein and RNA synthesis in the liver decreased the activities of both RNA-polymerases, the activity of RNA-polymerase II being inhibited stronger as compared to that of RNA-polymerase I.