Sodium-independent effect of aldosterone on initial rate of ouabain binding in A6 cells

Details

Serval ID
serval:BIB_C6005CB2672C
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Sodium-independent effect of aldosterone on initial rate of ouabain binding in A6 cells
Journal
American Journal of Physiology
Author(s)
Pellanda  A. M., Gaeggeler  H. P., Horisberger  J. D., Rossier  B. C.
ISSN
0363-6143
Publication state
Published
Issued date
04/1992
Volume
262
Number
4 Pt 1
Pages
C899-906
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Apr
Abstract
To estimate the early effect of aldosterone on the number of active Na(+)-K+ pumps at the basolateral membrane of amphibian tight epithelia, we have measured the initial rate (at 4 min) of [3H]ouabain binding to the basolateral membrane of intact monolayers of A6 cells grown on permeable supports. Within 3 h, aldosterone induced a threefold increase of the Na transport and, simultaneously, a twofold increase of the binding rate of ouabain. Because the affinity of ouabain, estimated either by equilibrium binding studies or inhibition kinetics, was not modified by aldosterone, the effect on the initial rate of ouabain binding was due to an increase in the number of binding sites. This effect on ouabain binding was not prevented by 10 microM amiloride, which reduced the transepithelial sodium transport below control level. By contrast, the effect of aldosterone on ouabain binding was abolished by cycloheximide (5 micrograms/ml) or actinomycin D (2 micrograms/ml), doses which inhibited the aldosterone-dependent sodium transport response. These data suggest that aldosterone elicits an early, sodium-independent, protein synthesis-dependent increase in the expression of active Na(+)-K(+)-ATPase molecules.
Keywords
Aldosterone/*pharmacology Animals Biological Transport/drug effects Cell Line Cycloheximide/pharmacology Cytological Techniques Dactinomycin/pharmacology Electric Conductivity Kidney/cytology/*metabolism Kinetics Ouabain/antagonists & inhibitors/*metabolism Sodium/metabolism/*physiology
Pubmed
Web of science
Create date
24/01/2008 12:38
Last modification date
20/08/2019 15:41
Usage data