Delayed DNA Synthesis Induced by 3‐Aminobenzamide in Partially Hepatectomized Liver of Rats

The possibility of poly(ADP‐ribosyl)ation playing a role during liver regeneration induced by partial hepatectomy (PH) in vivo was examined. When rats were given an i.p. injection of 3‐antinobenzamide (ABA) at a dose of 600 mg/kg body weight 12 h after PH, the levels of DNA synthesis at 20 h after PH were significantly reduced. The time course of DNA synthesis in regenerating liver was significantly delayed in the ABA‐treated group. Enzymatic assay revealed the activity of poly‐(ADP‐ribose)polymerase (PADPRP) in controls to be increased in parallel with the increase of DNA synthesis induced by PH. This increase in PADPRP activity was delayed and very much weaker after ABA treatment. The results thus suggested that poly (AUP‐ribosyl)ation might play an important role in DNA synthesis during liver regeneration in vivo.