Increase of nucleotidase activities in rat blood serum after a single convulsive injection of pentylenetetrazol.
Adenosine has been shown to be a major regulator in convulsive disorders exerting its anticonvulsant effects on various seizure models. The ectonucleotidase pathway is an important metabolic source of extracellular adenosine. In this study, we evaluated ATP, ADP and AMP hydrolysis in rat serum after a single convulsive injection of pentylenetetrazol (PTZ). The animals were sacrificed at 5 and 30 min, 1, 5, 12, 24 and 48 h after an intraperitoneal injection of PTZ (60 mg/kg). ATP, ADP and AMP hydrolysis by rat blood serum were significantly increased (40-50%) until 24 h after PTZ injection. There were no significant differences in the nucleotide hydrolysis when the in vitro effect of different concentrations of PTZ was analyzed. Changes in nucleotide hydrolysis observed after acute administration of PTZ could not be attributed to phosphodiesterase activity since PTZ-treated rats did not demonstrate significant differences in the hydrolysis of the substrate marker of this enzyme when compared with control rats. These results suggest that the stimulation of the nucleotidase pathway may play an important role in attenuating seizure activity.
Bruno
Alessandra Nejar
AN
Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Anexo Rua Ramiro Barcelos, 2600-90035-003 Porto Alegre, RS, Brazil.
Oses
Jean Pierre
JP
Bonan
Carla Denise
CD
Walz
Roger
R
Battastini
Ana Maria Oliveira
AM
Sarkis
João José Freitas
JJ
D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D007274:Injections, Intraperitoneal; D009708:Nucleotidases / Q000097:blood*; D010433:Pentylenetetrazole / Q000008:administration & dosage* / Q000009:adverse effects; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000097:blood* / Q000139:chemically induced / Q000201:enzymology
D009708:Nucleotidases; C030287:nucleotidase; D010433:Pentylenetetrazole