Endothelin receptor regulation by endothelin synthesis in vascular smooth muscle cells: effects of dexamethasone and phosphoramidon.
J Vasc Res
; 30(3): 139-44, 1993.
Article
in En
| MEDLINE
| ID: mdl-8518331
ABSTRACT
One of the major biological effects of the endothelium-derived peptide endothelin-1 (ET-1) is its receptor-mediated constrictive action on vascular smooth muscle. In this study, we have examined the effects on the ET-1 pathway of 18 h exposure at 37 degrees C of cultured rat aortic smooth muscle cells to dexamethasone (DEX) and phosphoramidon. ET-1 synthesis was evaluated by radioimmunoassay, ET-1 binding characteristics were determined with [125I]iodo-ET-1, and ET-1-induced intracellular calcium mobilization was measured using fura-2-loaded cells. DEX (100 nM) led to a 2- to 3-fold-increase of ET-1 production, it down-regulated ET-1 receptors and reduced ET-1-stimulated calcium mobilization by 70%. In contrast, phosphoramidon (100 microM) inhibited ET-1 production by 60%, up-regulated ET-1 receptors and potentiated ET-1-induced calcium mobilization by 75%. These results indicate that the regulatory effects of DEX and phosphoramidon on ET-1 receptors are mediated via ET-1 production by the cells. This suggests an autocrine control of ET-1 receptors by endogenous ET-1 synthesis in vascular smooth muscle cells.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Dexamethasone
/
Glycopeptides
/
Endothelins
/
Receptors, Endothelin
/
Muscle, Smooth, Vascular
Limits:
Animals
Language:
En
Journal:
J Vasc Res
Journal subject:
ANGIOLOGIA
Year:
1993
Document type:
Article
Affiliation country:
France