Effects in vitro of guanidinoacetate on adenine nucleotide hydrolysis and acetylcholinesterase activity in tissues from adult rats.
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.
Spanevello
Roselia Maria
RM
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.
de Souza Wyse
Angela Terezinha
AT
Mazzanti
Cinthia Melazzo
CM
Schmatz
Roberta
R
Stefanello
Naiara
N
Gonçalves
Jamile Fabbrin
JF
Bagatini
Margarete
M
Battisti
Vanessa
V
Morsch
Vera Maria
VM
Schetinger
Maria Rosa Chitolina
MR
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
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