Specific binding sites for corticosterone in isolated cells and plasma membrane from rat liver

The specific binding of [3H]corticosterone to hepatocytes is a nonsaturable, reversible and temperature-dependent process. The binding to liver purified plasma membrane fraction is also specific, reversible and temperature dependent but it is saturable. Two types of independent and equivalent bindin...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of membrane biology 1991-03, Vol.120 (2), p.115-124
Main Authors: TRUEBA, M, IBARROLA, I, OGIZA, K, MARINO, A, MACARULLA, J. M
Format: Article
Language:English
Subjects:
Animals
Binding Sites
Binding, Competitive
Biological and medical sciences
Cell Membrane - metabolism
cell membranes
Cell structures and functions
corticosterone
Corticosterone - metabolism
Fundamental and applied biological sciences. Psychology
In Vitro Techniques
Kinetics
Liver - drug effects
Liver - metabolism
Male
Molecular and cellular biology
Rats
Rats, Inbred Strains
Receptors, Steroid - metabolism
Steroids - metabolism
Sympatholytics - pharmacology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The specific binding of [3H]corticosterone to hepatocytes is a nonsaturable, reversible and temperature-dependent process. The binding to liver purified plasma membrane fraction is also specific, reversible and temperature dependent but it is saturable. Two types of independent and equivalent binding sites have been determined from hepatocytes. One of them has high affinity and low binding capacity (KD = 8.8 nM and Bmax = 1477 fmol/mg protein) and the other one has low affinity and high binding capacity (KD = 91 nM and Bmax = 9015 fmol/mg). In plasma membrane only one type of binding site has been characterized (KD = 11.2 nM and Bmax = 1982 fmol/mg). As it can be deduced from displacement data obtained in hepatocytes and plasma membrane the high affinity binding sites are different from the glucocorticoid, progesterone nuclear receptors and the Na+,K(+)-ATPase digitalis receptor. Probably it is of the same nature that the one determinate of [3H]cortisol and [3H]corticosterone in mouse liver plasma membrane. Beta- and alpha-adrenergic antagonists as propranolol and phentolamine did not affect [3H]corticosterone binding to hepatocytes and plasma membranes; therefore, these binding sites are independent of adrenergic receptors. The binding sites in hepatocytes and plasma membranes are not exclusive for corticosterone but other steroids are also bound with very different affinities.
ISSN:0022-2631
1432-1424
DOI:10.1007/bf01872394