Effect of ADP-Ribosyl Transferase Inhibitors on the Survival of Human Lymphocytes after Exposure to Different DNA-Damaging Agents (original) (raw)

ADP-ribosyl transferase (ADPRT) is a nuclear enzyme activated by single (SSB) and double (DSB) DNA strand breaks which synthesizes ADP-ribose homopolymers bound to nuclear proteins. The physiological role of ADPRT is still poorly understood, although it has been suggested that it plays a role in DNA repair and cell proliferation and differentiation.' Excessive activation of the enzyme can exhaust intracellular NAD+ and ATP pools, thereby contributing to the so-called suicide response of extensively damaged cells.* We asked whether ADPRT inhibitors, such as 3-aminobenzamide (3-ABA) and nicotinamide (NAM), would prevent the suicide response of human lymphocyte damaged by gamma rays in the same way as in lymphocytes damaged by oxygen