| Autor: |
Hagley RD; Department of Internal Medicine, Medical College of Virginia/VCU, Richmond 23219-0145, USA., Watlington CO |
| Jazyk: |
angličtina |
| Zdroj: |
Endocrine research [Endocr Res] 1996 Aug; Vol. 22 (3), pp. 221-35. |
| DOI: |
10.3109/07435809609030509 |
| Abstrakt: |
The A6 cell line, derived from Xenopus kidney, is an in vitro model of cortico-steroid mediated transepitheial Na+ transport stimulation. We report the apparent down-regulation of mineralocorticoid receptor levels in A6 cells, in response to the presence of the synthetic glucorticoid dexamethasone in the culture medium. Mineralocorticoid receptor binding was suppressed to approximately 25% of control following 24-hour exposure to 10nM dexamethasone. Scatchard analysis of concentration-binding experiments show down-regulation of maximum binding capacity by Dex exposure with no alteration of MR affinity, i.e., alteration of MR number only. The effect is dose-responsive with half-maximal down regulation at 1nM. Maximal inhibition of binding occurred after 24-hours exposure to dexamethasone. The inhibitory effect of dexamethasone on MR binding was unique for the glucocorticoid, with no effect exhibited following similar treatment with an androgen, an estrogen, or a mineralocorticoid. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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