Glucocorticoid stimulation of sodium absorption in colon epithelia is mediated by corticosteroid IB receptor
| Autor: | Gerald Litwack, Thomas J. Schmidt, C P Bastl, Carol A. Barnett |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
medicine.medical_specialty
Aldosterone Chemistry Sodium chemistry.chemical_element Stimulation Cell Biology Biochemistry Intestinal absorption chemistry.chemical_compound Glucocorticoid receptor Endocrinology Internal medicine medicine Receptor Molecular Biology hormones hormone substitutes and hormone antagonists Cation transport Glucocorticoid medicine.drug |
| Zdroj: | Journal of Biological Chemistry. 259:1186-1195 |
| ISSN: | 0021-9258 |
| DOI: | 10.1016/s0021-9258(17)43586-1 |
| Popis: | Studies with RU26988, a synthetic glucocorticoid which does not bind to aldosterone receptors, suggest glucocorticoid-induced colonic cation transport is affected through glucocorticoid-specific receptors. RU26988 produced a 700% increase in sodium absorption and doubled transmural potential difference in proximal and distal colon of adrenalectomized rats. Scatchard analysis suggested a single class of receptors with a KD of approximately 10(-9) M. Competition of unlabeled steroids for [3H]triamcinolone acetonide-binding sites paralleled the steroids' biologic potency as glucocorticoids. Heat treatment (25 degrees C, 30 min) markedly enhanced binding of the glucocorticoid-receptor complexes to DNA-cellulose. The activated receptor from both proximal and distal colon was eluted in the prewash from DEAE-Sephadex A-50 anion exchange columns both in the presence and absence of protease inhibitors and has an estimated molecular weight (Stokes radius) of 33,000-37,000 (25-26 A). These results identify the colonic receptor as glucocorticoid binder IB, a receptor previously identified as the major binder only in kidney cortex. The finding of an apparently unique receptor in the two tissues where glucocorticoids stimulate cation transport suggests that the phenotypic response mediated by glucocorticoids in different tissues might be determined by the structure of the receptor and that glucocorticoid binder IB is the glucocorticoid cation transport receptor. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|