Dissociation between the magnitude of nuclear binding and the biopotency of glucocorticoids.

Abstract:

:After 5 days of incubation with 10 nM tritiated dexamethasone, the amount of glucocorticoid displaceably-bound by the ACTH-secreting, glucocorticoid-responsive AtT-20 mouse pituitary tumor cell decreases by 70-80%. This decrease takes place in both the cytosolic and nuclear fractions. Although one might predict that there should be a decrease in agonist efficacy associated with this loss of nuclear binding, there was not; long-term incubations with dexamethasone revealed that the AtT-20 cells showed no tendency to resume secreting ACTH. Hence, although there was a dramatic decrease in the amount of nuclear-bound steroid, there was not a resulting decrease in the steroid's biopotency. These results suggest that the agonist-induced decrease in receptor content is either a means of removing redundant nuclear receptors, or a new, previously unrecognized, step in the mechanism of glucocorticoid hormone action.

journal_name

Endocrinology

journal_title

Endocrinology

authors

Svec F,Rudis M

doi

10.1210/endo-111-2-699

subject

Has Abstract

pub_date

1982-08-01 00:00:00

pages

699-702

issue

2

eissn

0013-7227

issn

1945-7170

journal_volume

111

pub_type

杂志文章