title: Methanol alters ecto-nucleotidases and acetylcholinesterase in zebrafish brain.
abstract: Methanol is a neurotoxic compound that is responsible for serious damage on CNS. Besides being found as an environmental contaminant, this alcohol is also employed as a component of cryoprotector solutions for zebrafish embryos. Here we tested the acute effect of methanol on ecto-nucleotidase (NTPDase, ecto-5'-nucleotidase) and acetylcholinesterase (AChE) activities in zebrafish brain. After acute treatment, there were significant decreases on ATP (26% and 45%) and ADP hydrolysis (26% and 30%) at 0.5% and 1.0%, respectively. However, no significant alteration on ecto-5'-nucleotidase activity was verified in zebrafish brain. A significant inhibition on AChE activity (39%, 33% and 30%) was observed at the range of 0.25% to 1.0% methanol exposure. Four NTPDase sequences were identified from phylogenetic analyses, which one is similar to NTPDase1 and the others to NTPDase2. Methanol was able to inhibit NTPDase1, two isoforms of NTPDase2 and AChE transcripts. To evaluate if methanol affects directly these enzymes activities, we have performed in vitro assays. ATP hydrolysis presented a significant inhibition (19% and 34%) at 1.5% and 3.0%, respectively, and ADP hydrolysis decreased only at 3.0% (29.2%). Nevertheless, AMP hydrolysis and AChE were not altered after in vitro exposure. The inhibitory effect observed on these enzymes could contribute to the neurodegenerative events promoted by methanol in zebrafish brain.
authors.affiliation: Laboratório de Neuroquímica e Psicofarmacologia, Departamento de Biologia Celular e Molecular, Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul. Avenida Ipiranga, 6681, 90619-900, Porto Alegre, RS, Brazil.
authors.forename: Eduardo Pacheco
authors.initials: EP
authors.lastname: Rico
authors.forename: Denis Broock
authors.initials: DB
authors.lastname: Rosemberg
authors.forename: Mario Roberto
authors.initials: MR
authors.lastname: Senger
authors.forename: Marcelo de Bem
authors.initials: Mde B
authors.lastname: Arizi
authors.forename: Giovana Farinon
authors.initials: GF
authors.lastname: Bernardi
authors.forename: Renato Dutra
authors.initials: RD
authors.lastname: Dias
authors.forename: Maurício Reis
authors.initials: MR
authors.lastname: Bogo
authors.forename: Carla Denise
authors.initials: CD
authors.lastname: Bonan
mesh_terms: D015720:5'-Nucleotidase / Q000096:biosynthesis / Q000378:metabolism*; D000110:Acetylcholinesterase / Q000096:biosynthesis / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D004790:Enzyme Induction; D005260:Female; D008297:Male; D000432:Methanol / Q000494:pharmacology*; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015027:Zebrafish / Q000502:physiology*
chemical_list: D009419:Nerve Tissue Proteins; D000255:Adenosine Triphosphate; D000110:Acetylcholinesterase; D015720:5'-Nucleotidase; D000432:Methanol