In:
American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, American Physiological Society, Vol. 276, No. 4 ( 1999-04-01), p. R1010-R1017
Abstract:
The central and peripheral cardiovascular effects of endothelin (ET)-1 and ET-3 were investigated in conscious rainbow trout. Both intracerebroventricular and intra-arterial injections of ET-1 (6.25–25 pmol) but not ET-3 (25 pmol) caused a dose-dependent increase in mean dorsal aortic blood pressure and a concomitant decrease in heart rate. The hypertensive effects induced by intra-arterial and intracerebroventricular injection of ET-1 were associated with a significant ( P 〈 0.05) increase in systemic vascular resistance. Intracerebroventricular injection of ET-1 induced a twofold higher pressor response than that caused by intra-arterial injection of ET-1 and provoked a barostatic gain that was reduced by 2.5- to 3-fold compared with that calculated after intra-arterial administration of the peptide. The ET receptor antagonist bosentan significantly ( P 〈 0.05) attenuated these responses regardless of the route of administration. Finally, intra-arterial injection of ET-1 did not significantly modify plasma cortisol level. The present data demonstrate that intracerebroventricular and intra-arterial administration of very low doses of ET-1 produces hypertension in conscious trout. The lack of effect of ET-3 indicates that the hemodynamic actions of ET-1 are mediated both centrally and peripherally through ET A receptors.
Type of Medium:
Online Resource
ISSN:
0363-6119
,
1522-1490
DOI:
10.1152/ajpregu.1999.276.4.R1010
Language:
English
Publisher:
American Physiological Society
Publication Date:
1999
detail.hit.zdb_id:
1477297-8
SSG:
12
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