Inhibitors of poly (ADP-ribose) synthesis inhibit the two types of repair of potentially lethal damage.
OBJECTIVE
The purpose of this study was to examine whether 3-amino-benzamide (3ABA), an inhibitor of poly (ADP-ribose) synthesis, inhibits the two types of potentially lethal damage (PLD) repair, termed slow and fast.


METHODS
The fast-type PLD repair was measured by the decrease in survival of V79 Chinese hamster cells by postirradiation treatment with 3ABA. The slow-type PLD repair was measured by the increase in survival by posttreatment with conditioned medium (CM), which became conditioned by growing a crowed culture of cells and supports the slow-type PLD repair.


RESULTS
Up to 1 mM, 3-ABA inhibited the slow type repair; at doses of 2 mM and above, it inhibited the fast type of PLD repair.


CONCLUSIONS
There are quantitative differences in cellular effects of 3ABA dependent on concentration. Poly (ADP-ribose) appears to play an important role in the PLD repairs and has little effect on the repair of sublethal damages.
Utsumi
H
H
Research Reactor Institute, Kyoto University, Osaka, Japan.
Elkind
M M
MM
D000818:Animals; D001549:Benzamides / Q000494:pharmacology*; D016466:CHO Cells; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D006224:Cricetinae; D004260:DNA Repair / Q000187:drug effects*; D000067856:Poly(ADP-ribose) Polymerase Inhibitors
D001549:Benzamides; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; C025160:3-aminobenzamide