Abstract: | The incorporation of [32P] orthophosphate into liver poly A-rich cytoplasmic RNA was investigated in rats which were pretreated with 3-methyl cholanthrene (3MC) or with the vehicle, corn oil. This incorporation was markedly increased within 6 h after administration of the polycyclic hydrocarbon and reached a maximum by 24 h, i.e., 33-fold increase. The poly A-rich RNA fraction was examined by gel electrophoresis and the specific activity of individual species was shown to be elevated. |