title: Changes in Na+, K+-ATPase activity and alpha 3 subunit expression in CNS after administration of Na+, K+-ATPase inhibitors.
abstract: The expression of Na(+), K(+)-ATPase α3 subunit and synaptosomal membrane Na(+), K(+)-ATPase activity were analyzed after administration of ouabain and endobain E, respectively commercial and endogenous Na(+), K(+)-ATPase inhibitors. Wistar rats received intracerebroventricularly ouabain or endobain E dissolved in saline solution or Tris-HCl, respectively or the vehicles (controls). Two days later, animals were decapitated, cerebral cortex and hippocampus removed and crude and synaptosomal membrane fractions were isolated. Western blot analysis showed that Na(+), K(+)-ATPase α3 subunit expression increased roughly 40% after administration of 10 or 100 nmoles ouabain in cerebral cortex but remained unaltered in hippocampus. After administration of 10 μl endobain E (1 μl = 28 mg tissue) Na(+), K(+)-ATPase α3 subunit enhanced 130% in cerebral cortex and 103% in hippocampus. The activity of Na(+), K(+)-ATPase in cortical synaptosomal membranes diminished or increased after administration of ouabain or endobain E, respectively. It is concluded that Na(+), K(+)-ATPase inhibitors modify differentially the expression of Na(+), K(+)-ATPase α3 subunit and enzyme activity, most likely involving compensatory mechanisms.
authors.affiliation: Instituto de Biología Celular y Neurociencias Prof E De Robertis, CONICET-UBA, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina. mgeraldineb@yahoo.com
authors.forename: María Geraldina
authors.initials: MG
authors.lastname: Bersier
authors.forename: Clara
authors.initials: C
authors.lastname: Peña
authors.forename: Georgina Rodríguez de Lores
authors.initials: GR
authors.lastname: Arnaiz
mesh_terms: D000818:Animals; D002490:Central Nervous System / Q000187:drug effects* / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D008297:Male; D010042:Ouabain / Q000031:analogs & derivatives / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D013574:Synaptosomes / Q000187:drug effects / Q000201:enzymology
chemical_list: D004791:Enzyme Inhibitors; C119205:endobain E; D010042:Ouabain; C541459:Atp1a3 protein, rat; D000254:Sodium-Potassium-Exchanging ATPase