title: Effects in vitro of guanidinoacetate on adenine nucleotide hydrolysis and acetylcholinesterase activity in tissues from adult rats.
abstract: Guanidinoacetate methyltransferase (GAMT) deficiency is a disorder of creatine metabolism characterized by low plasma creatine concentrations in combination with elevated guanidinoacetate (GAA) concentrations. The aim of this work was to investigate the in vitro effect of guanidinoacetate in NTPDase, 5'-nucleotidase and acetylcholinesterase activities in the synaptosomes, platelets and blood of rats. The results showed that in synaptosomes the NTPDase and 5'-nucleotidase activities were inhibited significantly in the presence of GAA at concentrations of 50, 100, 150 and 200 microM (P < 0.05). However, in platelets GAA at the same concentrations caused a significant increase in the activities of these two enzymes (P < 0.05). In relation to the acetylcholinesterase activity, GAA caused a significant inhibition in the activity of this enzyme in blood at concentrations of 150 and 200 microM (P < 0.05), but did not alter the acetylcholinesterase activity in synaptosomes from the cerebral cortex. Our results suggest that alterations caused by GAA in the activities of these enzymes may contribute to the understanding of the neurological dysfunction of GAMT-deficient patients.
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: Roselia Maria
authors.initials: RM
authors.lastname: Spanevello
authors.forename: Angela Terezinha
authors.initials: AT
authors.lastname: de Souza Wyse
authors.forename: Cinthia Melazzo
authors.initials: CM
authors.lastname: Mazzanti
authors.forename: Roberta
authors.initials: R
authors.lastname: Schmatz
authors.forename: Naiara
authors.initials: N
authors.lastname: Stefanello
authors.forename: Jamile Fabbrin
authors.initials: JF
authors.lastname: Gonçalves
authors.forename: Margarete
authors.initials: M
authors.lastname: Bagatini
authors.forename: Vanessa
authors.initials: V
authors.lastname: Battisti
authors.forename: Vera Maria
authors.initials: VM
authors.lastname: Morsch
authors.forename: Maria Rosa Chitolina
authors.initials: MR
authors.lastname: Schetinger
mesh_terms: D015720:5'-Nucleotidase / Q000378:metabolism*; D000110:Acetylcholinesterase / Q000378:metabolism*; D000227:Adenine Nucleotides / Q000378:metabolism*; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D001081:Apyrase / Q000378:metabolism*; D001921:Brain / Q000378:metabolism; D005998:Glycine / Q000031:analogs & derivatives* / Q000378:metabolism; D050937:Guanidinoacetate N-Methyltransferase / Q000378:metabolism; D006868:Hydrolysis; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013574:Synaptosomes / Q000378:metabolism
chemical_list: D000227:Adenine Nucleotides; D015703:Antigens, CD; D007527:Isoenzymes; D050937:Guanidinoacetate N-Methyltransferase; D000110:Acetylcholinesterase; D015720:5'-Nucleotidase; D001081:Apyrase; C067869:CD39 antigen; C004946:glycocyamine; D005998:Glycine