title: ADP-ribosylation and post-irradiation cellular recovery in two strains of L5178Y cells.
abstract: Two strains of murine lymphoma cells, L5178Y-R (LY-R) and L5178Y-S (LY-S) differ in radiosensitivity (D0 ca 1.0 and 0.5 Gy) In this cellular system we tested the influence of poly (adenosine diphosphoribose) transferase (ADPRT) inhibitors, benzamide and caffeine, in combination with X or gamma irradiation under aerobic conditions, on the cellular response. We found a small difference between LY-R and LY-S cell strains in incorporation of 3H from [3H]-NAD (nicotinamide dinucleotide) into permeabilized cells. The incorporation was related to DNA degradation initiated by the permeabilization procedure. The post-irradiation inhibition of DNA synthesis was reversed only in LY-S cells by 2mM benzamide or 2mM caffeine treatment. Changes in the cell cycle, as determined by flow-cytometry, were of similar character in both LY-R and LY-S cells, within 12 h after irradiation, whereas the effect of treatment on survival differed: only LY-S cells were radiosensitized by benzamide; both LY strains were sensitized by caffeine, but to different extents. From these observations it followed that there was a pattern of relations between the extent of postirradiation DNA synthesis, duration of mitotic delay and recovery.
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D000818:Animals; D001549:Benzamides / Q000494:pharmacology*; D002110:Caffeine / Q000494:pharmacology*; D002453:Cell Cycle; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002478:Cells, Cultured; D004273:DNA, Neoplasm / Q000096:biosynthesis*; D004307:Dose-Response Relationship, Radiation; D007940:Leukemia L5178 / Q000378:metabolism / Q000473:pathology*; D007942:Leukemia, Experimental / Q000473:pathology*; D051379:Mice; D009702:Nucleoside Diphosphate Sugars / Q000378:metabolism*; D009713:Nucleotidyltransferases / Q000037:antagonists & inhibitors; D011064:Poly Adenosine Diphosphate Ribose / Q000096:biosynthesis; D011065:Poly(ADP-ribose) Polymerases; D011836:Radiation Tolerance; D013997:Time Factors; D014316:Tritium
chemical_list: D001549:Benzamides; D004273:DNA, Neoplasm; D009702:Nucleoside Diphosphate Sugars; D014316:Tritium; D000246:Adenosine Diphosphate Ribose; D011064:Poly Adenosine Diphosphate Ribose; D002110:Caffeine; C037689:benzamide; D011065:Poly(ADP-ribose) Polymerases; D009713:Nucleotidyltransferases