Focal cerebral ischaemia induces a decrease in activity and a shift in ouabain affinity of Na+, K+-ATPase isoforms without modifications in mRNA and protein expression

Détails

ID Serval
serval:BIB_B0A17013852B
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Focal cerebral ischaemia induces a decrease in activity and a shift in ouabain affinity of Na+, K+-ATPase isoforms without modifications in mRNA and protein expression
Périodique
Brain Research
Auteur⸱e⸱s
Jamme  I., Barbey  O., Trouve  P., Charlemagne  D., Maixent  J. M., MacKenzie  E. T., Pellerin  L., Nouvelot  A.
ISSN
0006-8993 (Print)
Statut éditorial
Publié
Date de publication
02/1999
Volume
819
Numéro
1-2
Pages
132-42
Notes
Journal Article --- Old month value: Feb 20
Résumé
In a mouse model of focal cerebral ischaemia, we observed after 1 h of ischaemia, that the total Na+, K+-ATPase activity was decreased by 39.4%, and then did not vary significantly up to 6 h post-occlusion. In the sham group, the dose-response curves for ouabain disclosed three inhibitory sites of low (LA), high (HA) and very high (VHA) affinity. In ischaemic animals, we detected the presence of only two inhibitory sites for ouabain. After 1 h of permanent occlusion, the first site exhibited a low affinity while the second site presented an affinity intermediate between those of HA and VHA sites, which evolved after 3 h and 6 h of occlusion towards that of the VHA site. The presence of only two ouabain sites for Na+, K+-ATPase after ischaemia could result from a change in ouabain affinity of both HA and VHA sites (alpha2 and alpha3 isoforms, respectively) to form a unique component. Irrespective of the duration of ischaemia, the smaller activity of this second site accounted entirely for the loss in total activity. Surprisingly, no modifications in protein and mRNA expression of any alpha or beta isoforms of the enzyme were observed, thus suggesting that ischaemia could induce intrinsic modifications of the Na+, K+-ATPase.
Mots-clé
Animals Binding Sites Blotting, Northern Blotting, Western Cerebral Cortex/enzymology/metabolism Ischemic Attack, Transient/enzymology/*metabolism Isoenzymes/genetics/metabolism Male Mice Na(+)-K(+)-Exchanging ATPase/genetics/*metabolism Ouabain/*metabolism RNA, Messenger/*metabolism Time Factors
Pubmed
Web of science
Création de la notice
24/01/2008 13:17
Dernière modification de la notice
20/08/2019 15:19
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