title: In vitro studies of the influence of glutamatergic agonists on the Na+,K(+)-ATPase and K(+)-p-nitrophenylphosphatase activities in the hippocampus and frontal cortex of rats.
abstract: BACKGROUND
  The overstimulation of excitatory glutamatergic neurotransmission and the inhibition of Na(+),K(+)-ATPase enzymatic activity have both been implicated in neurotoxicity and are possibly related to the pathogenesis of epilepsy and neurodegenerative disorders. In the present study, we investigated whether glutamatergic stimulation by the glutamatergic agonists glutamate, α-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA), kainate and N-methyl-d-aspartate (NMDA) modulates the Na(+),K(+)-ATPase and the K(+)-p-nitrophenylphosphatase activities in the crude synaptosomal fraction of the hippocampus and the frontal cortex of rats.
  
  
  RESULTS
  Our results demonstrated that these glutamatergic agonists did not influence the activities of Na(+),K(+)-ATPase or K(+)-p-nitrophenylphosphatase in the brain structures analyzed. Assays with lower concentrations of ATP to analyze the preferential activity of the Na(+),K(+)-ATPase isoform with high affinity for ATP did not show any influence either.
  
  
  CONCLUSIONS
  These findings suggest that under our experimental conditions, the stimulation of glutamatergic receptors does not influence the kinetics of the Na(+),K(+)-ATPase enzyme in the hippocampus and frontal cortex.
authors.affiliation: Departamento de Psicobiologia, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, SP, Brazil. mmmarcos@uol.com.br
authors.forename: Marcos Brandão
authors.initials: MB
authors.lastname: Contó
authors.forename: Marco Antonio Campana
authors.initials: MA
authors.lastname: Venditti
mesh_terms: D009597:4-Nitrophenylphosphatase / Q000378:metabolism*; D000818:Animals; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D005625:Frontal Lobe / Q000187:drug effects* / Q000201:enzymology; D006624:Hippocampus / Q000187:drug effects* / Q000201:enzymology; D007608:Kainic Acid / Q000494:pharmacology; D008297:Male; D016202:N-Methylaspartate / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D009435:Synaptic Transmission; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
chemical_list: D018690:Excitatory Amino Acid Agonists; D016202:N-Methylaspartate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D009597:4-Nitrophenylphosphatase; D000254:Sodium-Potassium-Exchanging ATPase; D007608:Kainic Acid