EXPRESSION OF NMDA RECEPTOR SUBUNITS IS DIFFERENTIALLY MODIFIED BY ADMINISTRATION OF ENDOBAIN E, AN ENDOGENOUS Na/K-ATPase INHIBITOR.

M. G. BERSIER; C. PEÑA; G. RODRÍGUEZ DE LORES ARNAIZ.

Pinamar, Pcia. De Buenos Aires

Congreso; X Congreso de la Sociedad Panamericana de Bioquímica y Biología Molecular, XLI Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular, XX Reunión Anual de la Sociedad Argentina de Neuroquímica; 2005

Sociedad Panamericana de Bioquímica y Biología Molecular, Sociedad Argentina de Investigación en Bioquímica y Biología Molecular, Sociedad Argentina de Neuroquímica

EXPRESSION OF NMDA RECEPTOR SUBUNITS IS DIFFERENTIALLY MODIFIED BY ADMINISTRATION OF ENDOBAIN E, AN ENDOGENOUS Na+, K+-ATPase INHIBITOR Bersier, María G.; Peña, Clara and Rodríguez de Lores Arnaiz, Georgina. Inst. Biol. Cel. y Neuroc. “Prof. E. De Robertis”, Fac. Med., Cat. Farmacol. and IQUIFIB-CONICET, Fac. Farm. y Bioq., UBA. 1121-Buenos Aires, Argentina. E-mail: grodrig@ffyb.uba.ar   Previous studies showed that endobain E, an endogenous Na+, K+-ATPasa inhibitor, decreases dizocilpine binding to glutamatergic ionotropic NMDA receptor. In the search of interplay between NMDA receptor and Na+, K+-ATPasa, herein we analysed the expression of NMDA subunits after endobain E administration. Endobain E or saline (control) solutions were administered i.c.v. and 3 days later animals were decapitated, cerebral cortex and hippocampus removed and tissues were subjected to differential centrifugation to isolate crude membranes fractions. Western blot analysis by 7.5% SDS-PAGE were performed. Nitrocellulose membranes were blocked for 1 hour, then incubated with the antibodies against subunists NR1, NR2A and NR2B of NMDA receptor. The bands were visualised by quimiluminscence. After endobain E administration, expression of NR1, the most abundant subunit, highly increased in cerebral cortex and hippocampus. NR2A expression resulted enhanced or diminished in cerebral cortex and hippocampus, respectively. NR2B, the less abundant subunit, failed to change by the treatment. Results indicate that endobain E produced differential modifications in the expression of NMDA receptor subunits and support the hypothesis of a relationship between this receptor and Na+, K+-ATPasa.