Effect of tritium oxide on DNA structure of mammalian tissues

Tritium oxide was orally administered to rats in a dosage of 0.6 μCi per gram body weight. The total cumulative dose received for 37 days constituted 840 to 1140 rad. Radioactivity was revealed that was associated with endogenous DNA. The effect of tritium oxide induced single-stranded DNA breaks in nuclear lysates, which were registered during two weeks after treatment, and caused defects increasing the sensitivity of biopolymers to hydrodynamic and chemical affections during isolation of DNA preparations. RBE of tritium oxide was 3.3 as compared to 137Cs-γ-rays as assessed by the incidence of single-stranded DNA breaks in thymocytes in experiments in vitro