title: [Poly(ADP-ribosylation) of proteins determines the pool of endogenous NAD and the radiosensitivity of thymus lymphocytes].
abstract: A decrease in the endogenous NAD content that occurs immediately after gamma-irradiation of thymus lymphocytes is attributed to activation of poly (ADP-ribosylation) and not to changes in the activity of NAD-glycohydrolase and/or to the release of NAD from cells. The addition of benzamide 60 min before irradiation prevents the postirradiation drop of the NAD level and produces a radioprotective effect. At the same time, benzamide inhibits nuclear superhelix DNA repair and causes an average of 40 per cent decrease in the activity of DNA ligases I and II. The authors discuss the idea that the content of intracellular NAD in thymocytes is a critical factor responsible for the vitality of these cells.
mesh_terms: D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D011088:DNA Ligases / Q000378:metabolism; D004260:DNA Repair / Q000187:drug effects / Q000528:radiation effects; D004278:DNA, Superhelical / Q000187:drug effects / Q000528:radiation effects; D051379:Mice; D009243:NAD / Q000378:metabolism*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D011836:Radiation Tolerance; D013601:T-Lymphocytes / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects*
chemical_list: D001549:Benzamides; D004278:DNA, Superhelical; D009243:NAD; C037689:benzamide; D011065:Poly(ADP-ribose) Polymerases; D011088:DNA Ligases
vernacular_title: Poli(ADF-ribozilirovanie) belkov opredeliaet fond éndogennogo NAD i radiochuvstvitel'nost' limfotsitov timusa.