[en] The effect of γ-radiation on Tetrahymena under conditions that maintained the oxygen level during exposure was studied. Polyribosomes were dissociated after irradiation compared to controls but when cells were bubbled with oxygen dissociation was almost entirely prevented. Similarly radiation induced inhibition of protein synthesis was completely prevented when well oxygenated. It is suggested that when dissolved oxygen was controlled. Tetrahymena would provide a useful model for the study of radiation effects on DNA and protein metabolism in eukaryotic cells. (author)