title: Iron exposure modifies acetylcholinesterase activity in zebrafish (Danio rerio) tissues: distinct susceptibility of tissues to iron overload.
abstract: Iron is one the most abundant metals on the earth being essential for living organisms even though its free form can be toxic. The overload of this metal may be related with some disorders, like Alzheimer and Parkinson diseases, and hemochromatosis in the liver. The aim of the present study was to evaluate the effects of iron on acetylcholinesterase (AChE) activity in brain and liver of zebrafish and to investigate the possible correlation with the iron content in these tissues. Different corresponding concentrations of iron were tested using in vitro (0.018, 0.268, and 2.6 mM) and in vivo (1, 15, and 150 mg/l) assays. The in vitro studies showed that iron promoted a significant increase in AChE activity in brain (52%) and liver (53%) at the higher concentration (2.6 mM). In the in vivo assays, a significant increase in this enzyme activity was observed in the presence of 15 mg/l in both, brain (62%) and liver tissue (70%). Semiquantitative RT-PCR did not reveal significant changes in acetylthiocholinesterase mRNA levels. Moreover, we observed that iron content was significantly increased in liver tissue when exposed to 15 (226%) and 150 mg/l (200%). These results indicate that iron can promote significant alterations in AChE activity which probably is not directly related to the iron content in zebrafish tissues.
authors.affiliation: Laboratório de Biologia Genômica e Molecular, Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul, Avenida Ipiranga 6681, 90619-900 Porto Alegre, RS, Brazil.
authors.forename: M C B
authors.initials: MC
authors.lastname: Sant'Anna
authors.forename: Vanessa de Matas
authors.initials: Vde M
authors.lastname: Soares
authors.forename: Kelly Juliana
authors.initials: KJ
authors.lastname: Seibt
authors.forename: Gabriele
authors.initials: G
authors.lastname: Ghisleni
authors.forename: Eduardo Pacheco
authors.initials: EP
authors.lastname: Rico
authors.forename: Denis Broock
authors.initials: DB
authors.lastname: Rosemberg
authors.forename: Jarbas Rodrigues
authors.initials: JR
authors.lastname: de Oliveira
authors.forename: Nadja
authors.initials: N
authors.lastname: Schröder
authors.forename: Carla Denise
authors.initials: CD
authors.lastname: Bonan
authors.forename: Mauricio Reis
authors.initials: MR
authors.lastname: Bogo
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D007501:Iron / Q000633:toxicity*; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008297:Male; D015027:Zebrafish / Q000378:metabolism*
chemical_list: D007501:Iron; D000110:Acetylcholinesterase