Rapid eye movement sleep deprivation induces changes in the high-affinity binding of [H-3]-ouabain to the rat cortical membranes

Rapid eye movement sleep deprivation induces changes in the high-affinity binding of [H-3]-ouabain to the rat cortical membranes

Author Bignotto, Magda Google Scholar
Andrade, UJA de Google Scholar
Carvalho, JGB de Google Scholar
Venditti, Marco Antonio Campana Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Abstract Rapid eye movement sleep (REMS) suppresses seizures. On the other hand, REMS deprivation (REMSD) increases brain susceptibility to seizures. Sodium-postassium/ATPase is involved in the control of brain excitability. Ouabain, a cardiotonic glycoside, binds to a regulatory extracellular allosteric site in the sodium-potassium/ATPase inhibiting/stimulating its activity depending on its concentration. Endogenous ouabain-like substances exist in the brain; therefore, changes in the ouabain binding site may be involved in the increased brain excitability induced by REMSD. Adult, Wistar male rats were deprived of REMS for 96 hours by the flower-pot method (REMSD). A stress control group was kept in the same environment on a larger platform (LP). A third group of rats was kept in the same room in their home-cages (CONTROL). After REMSD all rats were sacrificed by decapitation and their cerebral cortex dissected. High-affinity [H-3]-ouabain binding was carried out in cortical crude membrane preparation using 8 concentrations of [H-3]-ouabain (1-24 nM). the results show a statistically significant increase of KID in the REMSD rats compared to both CONTROL and LP groups. There were no statistically significant differences in th B-max among the experimental groups. There was also no change either in cortical activity of K+ stimulated p-nitrophenylphosphatase, the dephosphorylation reaction of phosphorylated sodium-potassium/ATPase or in Mg2+-stimulated p-nitrophenylphosphatase. An increase in the KD of [H-3]-ouabain binding to the sodium-potassium/ATPase in REMSD rats indicates a lower affinity to the endogenous inhibitors/stimulators of the enzyme. Therefore, this decreased affinity of the endogenous ouabain-like substances may be involved in the increased excitability induced by REMSD. (c) 2005 Elsevier Ireland Ltd. All rights reserved.
Keywords REM sleep deprivation
cerebral cortex
[H-3]-ouabain
Na+-K(+)ATPase
brain excitability
Language English
Date 2006-03-27
Published in Neuroscience Letters. Clare: Elsevier B.V., v. 396, n. 2, p. 143-147, 2006.
ISSN 0304-3940 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 143-147
Origin http://dx.doi.org/10.1016/j.neulet.2005.11.027
Access rights Closed access
Type Article
Web of Science ID WOS:000235861900013
URI http://repositorio.unifesp.br/handle/11600/28795

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