Pressor responses to endothelin-1 in normotensive and spontaneously hypertensive rats

• Published in: Neurochemistry international Vol. 18; no. 4; p. 553
• Main Authors: Martel, E, Champeroux, P, Brisac, A M, Magnier, A, Richard, S, Safar, M
• Format: Journal Article
• Language: English
• Published: England 1991
• ISSN: 0197-0186
• DOI: 10.1016/0197-0186(91)90155-7

In freely moving rats, endothelin-1 (0.0135-4.5 nmol/kg) administered as an intravenous bolus injection, produced an immediate, short-lasting, dose-related fall in blood pressure followed by a long-lasting, dose-related increase in blood pressure. There was a higher sensitivity in the pressor responses to endothelin-1, in spontaneously hypertensive (SH) rats (ED(50) = 0.11 +/- 0.02 and 0.28 +/- 0.02 nmol/kg, in SH and normotensive rats, respectively), but no change in the maximal pressor effect of endothelin-1 in SH rats. In rat isolated aorta, endothelin-1 induced a greater vasocontractile effect in SH rats than in normotensive rats. In both rat strains, removal of the endothelium did not change the concentration-effect curves obtained in endothelium-intact preparations. These data add further support to the hypothesis that endothelin-1 could play a role in genetic hypertension, at least in the maintenance of high blood pressure.