The interaction of [3H]ethyl carbamate with nucleic acids of regenerating mouse liver

The binding of [3H]urethane to liver DNA and RNA has been examined in partially hepatectomised and intact male Crackenbush mice. A single dose of [3H]urethane (50 μCi) was given to non-hepatectomised mice (group A) and to 3 groups of partially hepatectomised mice at 18 (B), 28 (C) and 38 (D) hours postoperatively, respectively. The binding was examined over the subsequent 16 h. The maximum levels of binding to DNA declined in the order, group A > B > C > D, although the binding to DNA persisted longest in group B. The binding to RNA was greater in groups B, C and D than in group A. Neither the restoration of liver mass nor an alteration in the metabolism of urethane appeared to account for the different levels of binding. In normal and partially hepatectomised mice a single dose of urethane (20 mg) was followed by an inhibition of mitosis and of the incorporation of [3H]thymidine into liver DNA and of [3H]uridine into liver RNA