title: Ethidium bromide inhibits rat brain acetylcholinesterase activity in vitro.
abstract: Ethidium bromide (EtBr), a fluorescent dark red compound and stain for double-stranded DNA and RNA was used to study acetylcholinesterase (AChE) activity in vitro together with kinetic parameters of this enzyme in the striatum (ST), hippocampus (HP), cerebral cortex (CC) and cerebellum (CB) of adult rats. AChE activity in vitro in the ST, HP, CC and CB was significantly reduced (p<0.05) in the presence of EtBr at concentrations of 0.00625, 0.0125, 0.025, 0.05 and 0.1 mM. For the analysis of the kinetic three concentrations of EtBr were tested (0.00625, 0.025 and 0.1 mM). An uncompetitive inhibition type was observed in the ST, HP and CC, whereas in the CB the inhibition type was mixed. These data indicate that EtBr should be considered a strong inhibitor of AChE activity demonstrating that there is an interaction between this compound and the cholinergic system.
authors.affiliation: Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcellos, 2600-Anexo 90035-003, Porto Alegre, RS, Brazil.
authors.forename: Cinthia M
authors.initials: CM
authors.lastname: Mazzanti
authors.forename: Roselia M
authors.initials: RM
authors.lastname: Spanevello
authors.forename: Adriana
authors.initials: A
authors.lastname: Obregon
authors.forename: Luciane B
authors.initials: LB
authors.lastname: Pereira
authors.forename: Cristiane A
authors.initials: CA
authors.lastname: Streher
authors.forename: Mushtaq
authors.initials: M
authors.lastname: Ahmed
authors.forename: Alexandre
authors.initials: A
authors.lastname: Mazzanti
authors.forename: Dominguita L
authors.initials: DL
authors.lastname: Graça
authors.forename: Vera M
authors.initials: VM
authors.lastname: Morsch
authors.forename: Maria Rosa C
authors.initials: MR
authors.lastname: Schetinger
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry* / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002384:Catalysis / Q000187:drug effects; D002531:Cerebellum / Q000201:enzymology; D002540:Cerebral Cortex / Q000201:enzymology; D002800:Cholinesterase Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D003342:Corpus Striatum / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D004996:Ethidium / Q000737:chemistry* / Q000494:pharmacology; D006624:Hippocampus / Q000201:enzymology; D007700:Kinetics; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D002800:Cholinesterase Inhibitors; D000110:Acetylcholinesterase; D004996:Ethidium