The expression of NMDA receptor subunits in cerebral cortex and hippocampus is differentially increased by administration of endobain E, a Na+, K+-ATPase inhibitor.
Previous studies showed that endobain E, an endogenous Na+, K+-ATPase inhibitor, decreases dizocilpine binding to NMDA receptor in isolated membranes. The effect of endobain E on expression of NMDA receptor subunits in membranes of rat cerebral cortex and hippocampus was analyzed by Western blot. Two days after administration of 10 mul endobain E (1 microl = 29 mg fresh tissue) NR1 subunit expression enhanced 5-fold and 2.5-fold in cerebral cortex and hippocampus, respectively. NR2A subunit expression increased 2-fold in cerebral cortex and 1.5-fold in hippocampus. The level of NR2B subunit raised 3-fold in cerebral cortex but remained unaltered in hippocampus. NR2C subunit expression was unaffected in either area. NR2D subunit enhanced 1.6 and 2.1-fold for cerebral cortex and hippocampus, respectively. Results indicate that endogenous Na+, K+-ATPase inhibitor endobain E differentially modifies the expression of NMDA receptor subunits.
Instituto de Biología Celular y Neurociencias Prof. E. De Robertis, Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, Buenos Aires 1121, Argentina.
María Geraldina
MG
Bersier
Clara
C
Peña
Georgina
G
Rodríguez de Lores Arnaiz
D000818:Animals; D015153:Blotting, Western; D002540:Cerebral Cortex / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010042:Ouabain / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
D004791:Enzyme Inhibitors; D016194:Receptors, N-Methyl-D-Aspartate; C119205:endobain E; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase