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.

Immunohistochemical distribution of proteins involved in glutamate release in subepithelial sensory nerve endings of rat epiglottis

“…Na + -K + -ATPase α 3 subunit (NKAα 3 ): a mouse monoclonal anti NKAα 3 antibody (clone, XVIF9-G10: ab2826, Abcam, Cambridge, UK) was raised against full-length native protein (purified) corresponding to dog NKA from canine cardiac microsomes (Arystarkhova and Sweadner 1996). An immunoblotting analysis of this antibody labeled a 110 kDa protein band in cerebral cortex and hippocampus (Bersier et al 2011). Laryngeal laminar nerve endings were immunoreactive to this antibody (Soda and Yamamoto 2012).…”