Modulation of Na+,K+-ATPase activity is of importance for RVD
2004 (English)In: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 180, no 4, 329-334 p.Article in journal (Refereed) Published
Aim: This study was performed to examine the role of Na+,K+-ATPase activity for the adaptive response to cell swelling induced by hypoosmoticity, i.e. the regulatory volume decrease (RVD). Methods: The studies were performed on COS-7 cells transfected with rat Na+,K+-ATPase. To study changes in cell volume, cells were loaded with the fluorescent dye calcein and the intensity of the dye, following exposure to a hypoosmotic medium, was recorded with confocal microscopy. Results: Ouabain-mediated inhibition of Na+,K+-ATPase resulted in a dose dependent decrease in the rate of RVD. Total Rb-86(+) uptake as well as ouabain dependent Rb-86(+) uptake, used as an index of Na+,K+-ATPase dependent K+ uptake, was significantly increased during the first 2 min following exposure to hypoosmoticity. Since protein kinase C (PKC) plays an important role in the modulation of RVD, a study was carried out on COS-7 cells expressing rat Na+,K+-ATPase, where Ser23 in the catalytic alpha1 subunit of rat Na+,K+-ATPase had been mutated to Ala (S23A), abolishing a known PKC phosphorylation site. Cells expressing S23A rat Na+,K+-ATPase exhibited a significantly lower rate of RVD and showed no increase in Rb-86(+) uptake during RVD. Conclusion: Taken together, these results suggest that a PKC-mediated transient increase in Na+,K+-ATPase activity plays an important role in RVD.
Place, publisher, year, edition, pages
2004. Vol. 180, no 4, 329-334 p.
cell volume, Na+, K+-ATPase, protein kinase C, regulatory volume decrease, protein-kinase-c, regulatory volume decrease, 4th transmembrane segment, rat-kidney na+, k+-atpase, cell-volume, phosphorylation site, alpha-subunit, na+, permeability, activation
IdentifiersURN: urn:nbn:se:kth:diva-23267DOI: 10.1111/j.1365-201X.2003.01256.xISI: 000220306100002ScopusID: 2-s2.0-1942438089OAI: oai:DiVA.org:kth-23267DiVA: diva2:341965
QC 20100525 QC 201110282010-08-102010-08-102011-10-28Bibliographically approved