Abstract
Injection of ANGII (0.01, 0.1 and 1 nmol/rat) into the periaqueductal gray (PAG) area significantly (P<0.01) increased, in a dose-dependent manner, the mean arterial blood pressure (MAP). The increases in blood pressure induced by ANGII (1 nmol; 37 +/- 4 mmHg, n=5) were greatly reduced (>85%) by pre-administration of the ET(A) receptor antagonist FR139317 (5 nmol/rat) to the PAG area, but were unaffected by the ET(B) receptor antagonist BQ-788 (5 nmol/rat). SB209670, non-selective ET(A)/ET(B) receptor antagonist, also reduced the effect induced by ANGII. These results suggest that endogenous endothelin-1, via an action on ET(A) receptors, may contribute to the pressor effects of ANGII within the PAG area of rats.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Angiotensin II / pharmacology*
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Animals
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Azepines / pharmacology
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Blood Pressure / drug effects*
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Dose-Response Relationship, Drug
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Endothelin Receptor Antagonists*
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Endothelin-1 / physiology
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Indans / pharmacology
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Indoles / pharmacology
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Male
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Oligopeptides / pharmacology
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Periaqueductal Gray / drug effects*
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Piperidines / pharmacology
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Rats
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Rats, Sprague-Dawley
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Receptor, Endothelin A
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Receptor, Endothelin B
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Receptors, Endothelin / physiology
Substances
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Azepines
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Endothelin Receptor Antagonists
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Endothelin-1
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Indans
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Indoles
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Oligopeptides
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Piperidines
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Receptor, Endothelin A
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Receptor, Endothelin B
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Receptors, Endothelin
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1H-Indene-2-carboxylic acid, 1-(1,3-benzodioxol-5-yl)-3-(2- (carboxymethoxy)-4-methoxyphenyl)-2,3-dihydro-5-propoxy-, (1S,2R,3S)-
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Angiotensin II
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FR 139317
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BQ 788