title: Effect of procainamide and hydralazine on poly (ADP-ribosylation) in cell lines.
abstract: The prescription drugs procainamide (PA) and hydralazine (HYD) are associated with the induction of autoimmunity and a clinical syndrome called drug-induced lupus. Since PA- and HYD-induced autoantibodies are directed primarily against histones and histones are prime acceptors of poly (ADP-ribose) (PADPR), we have investigated the effects of PA and HYD on the activity of poly (ADP-ribose) polymerase (PADPRP). Control substances, with structures similar to PA and HYD but not known to induce lupus, included N-acetylprocainamide (NAPA) and the amino acids phenylalanine, tryptophan and proline, and their amide derivatives. Wil-2 cells were incubated in 0.5-50 microM PA, NAPA and HYD, which included therapeutic concentrations of these drugs. The mean enhancement of incorporation of [3H]-nicotinamide adenine dinucleotide (NAD) into PADPR was 1.84 (P = 0.005) with PA, with HYD 1.48 (P = 0.029), and with NAPA 1.38 (P = 0.036). This increase was suppressed by 3-aminobenzamide, an inhibitor of PADPRP activity. Little or no increase in [3H]-NAD incorporation was observed with equivalent concentrations of phenylalanine, phenylalaninamide or tryptophan. However, a 1.29-fold increase was noted with 0.5 microM tryptophanamide, a 1.26-fold increase with 0.5 microM prolinamide and a 1.4-fold increase with 50 microM proline. PA increased PADPRP activity in B- and T-cell lines but not in promyelocytic leukemia or epithelial cell lines. Since poly (ADP-ribosylation) is important in the cellular response to various agents, the increased ADP-ribosylation of intracellular molecules may be a key event in the induction of autoantibodies.
authors.affiliation: Joint Injury and Arthritis Research Group, University of Calgary, Alberta, Canada.
authors.forename: L M
authors.initials: LM
authors.lastname: Ayer
authors.forename: S M
authors.initials: SM
authors.lastname: Edworthy
authors.forename: M J
authors.initials: MJ
authors.lastname: Fritzler
mesh_terms: D000120:Acecainide / Q000494:pharmacology; D002461:Cell Line, Transformed; D006801:Humans; D006830:Hydralazine / Q000494:pharmacology*; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011342:Procainamide / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D011064:Poly Adenosine Diphosphate Ribose; D006830:Hydralazine; D000120:Acecainide; D011065:Poly(ADP-ribose) Polymerases; D011342:Procainamide