Angiotensin II increases the release of endothelin-I from human cultured endothelial cells but does not regulate its circulating levels

Autor: Anna Santucci, Cesare Bellini, Giovambattista Desideri, Giancarlo De Mattia, Marco Valenti, Claudio Ferri, R. Baldoncini
Rok vydání: 1999
Předmět:
Zdroj: Clinical Science. 96:261-270
ISSN: 1470-8736
0143-5221
Popis: We investigated the effect of angiotensin II on endothelin-I secretion in vitro and in vivo. In vivo, angiotensin II was given intravenously to 23 essential hypertensive and 8 control subjects according to different protocols: Study A, 1.0 ng min -1 .kg -1 and 3.0 ng min -1 .kg -1 angiotensin II for 30 min each; Study B, 1.0 ng.min -1 .kg -1 and 3.0 ng.min -1 .kg -1 angiotensin II for 120 min each; Study C, 3.0 ng.min -1 .kg -1 angiotensin II for 30 min followed by a dose increment of 3.0 ng.min -1 .kg -1 every 30 min until mean blood pressure levels increased by 25 mmHg; Study D, 1.0 ng.min -1 .kg -1 followed by 3.0 ng.min -1 .kg -1 angiotensin II for 60 min each on two different NaCl diets (either 20 mmol NaCl/day or 220 mmol NaCl/day, both for I week). In all in vivo studies neither plasma nor urine endothelin- I levels changed with angiotensin II infusion. In contrast, angiotensin II (10 -9 , 10 -8 , 10 -7 mol/l) stimulated endothelin-l secretion from cultured human vascular endothelial cells derived from umbilical cord veins in a time- and dose-dependent manner. The in vitro angiotensin II effects were abolished by candesartan cilexetil, an inhibitor of the membrane-bound AT 1 receptor, and also by actinomycin D, an RNA synthesis inhibitor, and cycloheximide, a protein synthesis inhibitor, indicating that endothelin-l release depended on AT 1 receptor subtype and de novo protein synthesis. Our findings indicate that angiotensin II regulates endothelin-I release by cultured endothelial cells through an AT 1 receptor-dependent pathway, but does not influence circulating endothelin-l levels in vivo.
Databáze: OpenAIRE
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