EurekaMag.com logo
+ Site Statistics
References:
53,623,987
Abstracts:
29,492,080
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on LinkedInFollow on LinkedIn

+ Translate

Effect of aldosterone on abundance and phosphorylation kinetics of Na-K-ATPase of toad urinary bladder



Effect of aldosterone on abundance and phosphorylation kinetics of Na-K-ATPase of toad urinary bladder



American Journal of Physiology 246(4 Pt 2): F509-F516



The possibility was explored that aldosterone-dependent modulation of either the abundance or the kinetic properties of the Na+ pump (Na-K-ATPase) is involved in the mechanism of natriferic action on toad urinary bladder. Cell membranes from the epithelium of urinary bladders of toads were prepared by a sucrose-Ficoll step gradient method, which yielded a 10-fold increase in specific activity of plasma membrane marker enzymes and only minor contamination with other subcellular fractions. Phosphorylation of Na-K-ATPase by gamma-PO4 of [gamma-32P]ATP in the presence of Mg2+ was Na+ dependent, whereas dephosphorylation was K+ dependent. Km for phosphorylation by ATP was 3 X 10(-8) M and K1/2 (half-maximal stimulation) for Na+ was 13 +/- 2 mM. Pretreatment of cell membranes with sodium deoxycholate (DOC) increased the maximal extent of phosphorylation (Nmax) about threefold without changing the Km for ATP. Aldosterone (5 X 10(-8) M) stimulated transepithelial Na+ transport two- to threefold in 5 h but had no significant effect on Km for ATP in the phosphorylation reaction (with or without activation by DOC) or on the abundance of the enzyme inferred from Nmax of phosphorylation in the absence of activation by DOC. After pretreatment with DOC, average Nmax was 13% greater in the aldosterone-treated population. Regression analysis of these responses revealed no significant correlation between increments in short-circuit currents and Nmax values of phosphorylation with or without pretreatment with DOC.

(PDF 0-2 workdays service: $29.90)

Accession: 017870594

Download citation: RISBibTeXText

PMID: 6326593



Related references

Effect of aldo sterone on abundance and phosphorylation kinetics of sodium potassium atpase of toad bufo marinus urinary bladder. American Journal of Physiology 246(4 PART 2): F509-F516, 1984

Effect of aldo sterone on phosphorylation kinetics of sodium potassium atpase of toad urinary bladder. Federation Proceedings 38(3 PART 1): 1240, 1979

Ultrastructural observations on the aldosterone-stimulated toad urinary bladder epithelium-ATPase activity. Journal of Ultrastructure Research 44(5): 339-346, 1973

The effect of aldosterone of glycolysis in the urinary bladder of the toad. Journal of Biological Chemistry 244(12): 3194-3199, 1969

Effect of aldosterone on cyclic-AMP metabolism in the urinary bladder of the toad. Experimental Eye Research 16(4): 235-240, 1973

Hormonal regulation of (Na+,K+)-ATPase biosynthesis in the toad bladder. Effect of aldosterone and 3,5,3'-triiodo-L-thyronine. Journal of Biological Chemistry 257(17): 10338-10343, 1982

The effect of aldosterone on cyclic nucleotide phosphodiesterase activity in toad urinary bladder. Life Sciences 13(5): 545-552, 1973

Effect of aldosterone on the sodium content and energy metabolism of epithelial cells of the toad urinary bladder. Journal of Steroid Biochemistry 3(2): 137-141, 1972

The effect of temperature and substrate concentration on the kinetics of (6- 3 H)uridine incorporation into RNA of toad bladder epithelial cells: the role of aldosterone. Biochimica et Biophysica Acta 281(1): 55-68, 1972

The role of bacterial contamination in isolated toad urinary bladder: effect of antibiotics on aldosterone-stimulated active sodium transport and RNA specific activity. Research Communications in Chemical Pathology and Pharmacology 3(3): 585-594, 1972

Energetics of sodium transport in the urinary bladder of the toad. Effect of aldosterone and sodium cyanide. Journal of Clinical Investigation 73(1): 46-52, 1984

Aldosterone-induced protein in toad urinary bladder. Science 186(4160): 269-272, 1974

Time-dependent aldosterone metabolism in toad urinary bladder. American Journal of Physiology 254(4 Pt 2): F547-F553, 1988

Glyoxylate cycle in toad urinary bladder: possible stimulation by aldosterone. Proceedings of the National Academy of Sciences of the United States of America 77(3): 1521-1525, 1980

Identification of aldosterone-induced proteins in the toad's urinary bladder. Proceedings of the National Academy of Sciences of the United States of America 72(10): 4056-4060, 1975