title: Further evidence for a different mode of action of caffeine and benzamide on mammalian cells.
abstract: Post-treatment with 2 mM caffeine or 2 mM benzamide increased the lethality of MNNG (N-methyl-N'-nitro-N-nitrosoguanidine) treated V79 cells; in the presence of 50 microM deoxycytidine, the caffeine effect was eliminated whereas the benzamide effect remained the same. Combined treatment with caffeine/benzamide alone produced a large amount of cell lethality which was eliminated by 50 microM deoxycytidine. Benzamide produced a strong inhibition of the poly(ADP-ribose)polymerase activity present in cell-free extracts prepared from V79 cells with greater than 90% inhibition at 2 mM concentration; caffeine on the other hand did not produce any substantial inhibition of this activity in the 2-5 mM range. These results further substantiate our earlier hypothesis that the mode of action of caffeine and benzamide on eukaryotic cells containing DNA damage are not identical [S.K. Das, C.C. Lau and A.B. Pardee (1984) Mutation Res., 131, 71-79].
mesh_terms: D000818:Animals; D001549:Benzamides / Q000008:administration & dosage / Q000633:toxicity*; D002110:Caffeine / Q000008:administration & dosage / Q000633:toxicity*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D006224:Cricetinae; D004260:DNA Repair / Q000187:drug effects*; D004357:Drug Synergism; D008769:Methylnitronitrosoguanidine / Q000633:toxicity; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism
chemical_list: D001549:Benzamides; D008769:Methylnitronitrosoguanidine; D002110:Caffeine; C037689:benzamide; D011065:Poly(ADP-ribose) Polymerases