Glucocorticoid receptor activation in isolated perfused rat hearts

S. M. Czerwinski, E. E. McKee, R. C. Hickson

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The formation of unactivated and activated glucocorticoid receptor complexes was studied in intact, isolated, perfused rat hearts in the presence of [3H]triamcinolone acetonide. Receptor activation, as quantified by the DNA-cellulose-binding assay, began to increase within 30 s of perfusion and reached a final steady-state level (t( 1/2 ) = 4.6 min) with 46% of the steroid-receptor complexes bound to DNA-cellulose. With the use of a linear potassium phosphate (KP) gradient (5-400 mM), unactivated receptors eluted from DEAE-cellulose anion exchange columns at ~250 mM KP. Two activated receptor forms appeared, which eluted either in the wash fraction (binder IB) or between 50 and 100 mM KP (binder II) and occurred with half times of 1.3 and 2.7 min, respectively. Postperfusion cytosol preparation did not markedly influence the results as receptor binding was reduced by 10% or less when a 100-fold excess of unlabeled triamcinolone acetonide was included in the homogenizing buffer. We conclude from these results that glucocorticoids are able to exert a direct effect on the heart through binding to their own receptor in the absence of endogenous hormones. The time dependency of receptor activation supports a physiological role for this process. However, activation rates, determined from conformational changes associated with altered DEAE-cellulose elution profiles and appearance of activated forms, occur earlier and may not be coordinated with the rate of activation as quantified by DNA-cellulose binding.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Cell Physiology
Volume256
Issue number2
StatePublished - 1989
Externally publishedYes

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Glucocorticoid Receptors
Rats
Triamcinolone Acetonide
DEAE-Cellulose
Chemical activation
Physiological Phenomena
Binders
Steroid Receptors
Cytosol
Glucocorticoids
Anions
Buffers
Perfusion
Hormones
Assays
DNA-cellulose

ASJC Scopus subject areas

  • Cell Biology
  • Clinical Biochemistry
  • Physiology

Cite this

Glucocorticoid receptor activation in isolated perfused rat hearts. / Czerwinski, S. M.; McKee, E. E.; Hickson, R. C.

In: American Journal of Physiology - Cell Physiology, Vol. 256, No. 2, 1989.

Research output: Contribution to journalArticle

Czerwinski, S. M. ; McKee, E. E. ; Hickson, R. C. / Glucocorticoid receptor activation in isolated perfused rat hearts. In: American Journal of Physiology - Cell Physiology. 1989 ; Vol. 256, No. 2.
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