Relationship between Na+, K+-ATPase and NMDA receptor at central synapses.

Specific receptors for classical neurotransmitters and neuropeptides, as well as the Na(+), K(+)-ATPase, are all molecular entities inserted into synaptic region membranes and localized contiguously. Herein, available experimental evidence showing close interactions between the activity of the Na(+), K(+)-ATPase and the N-methyl-D-aspartate (NMDA) ionotropic glutamate receptor was reviewed, supporting a functional link between these macromolecules. The Na(+), K(+)- ATPase and NMDA receptor are involved in ion movements through membranes.

Changes in Na+, K+-ATPase activity and alpha 3 subunit expression in CNS after administration of Na+, K+-ATPase inhibitors.

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.

Intracerebroventricular administration of ouabain to rats changes the expression of NMDA receptor subunits in cerebral cortex and hippocampus.

Ouabain exerts neurotoxic action and activates the population of NMDA receptors. Herein the effect of ouabain on the expression of NMDA subunits was evaluated. Adult Wistar rats were administered intracerebroventricularly with 0.

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.