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Angiotensin II dilates bovine adrenal cortical arterioles: role of endothelial nitric oxide. Endocrinology 2005 Aug;146(8):3319-24

Date

05/14/2005

Pubmed ID

15890772

DOI

10.1210/en.2005-0129

Scopus ID

2-s2.0-23044450565   21 Citations

Abstract

Adrenal steroidogenesis is modulated by humoral and neuronal factors and blood flow. Angiotensin II (AII) stimulates adrenal cortical aldosterone and cortisol production and medullary catecholamine release. However, AII regulation of adrenal vascular tone has not been characterized. We examined the effect of AII on diameters of cannulated bovine adrenal cortical arteries. Cortical arteries (average internal diameter = 230 microm) were constricted with U46619 and concentration-diameter responses to AII (10(-13) to 10(-8) mol/liter) were measured. In endothelium-intact arteries, AII induced dilations at low concentrations (maximum dilation = 25 +/- 6% at 10(-10) mol/liter) and constrictions at high concentrations (maximum constriction = 25 +/- 18% at 10(-8) mol/liter). AII constrictions were blocked by the angiotensin type 1 (AT1) receptor antagonist, losartan (10(-6) mol/liter). AII dilations were enhanced by losartan (maximal dilation = 48 +/- 8%), abolished by endothelial cell removal or N-nitro-L-arginine (L-NA, 3 x 10(-5) mol/liter) and inhibited by the angiotensin type 2 (AT2) receptor antagonist, PD123319 (10(-6) mol/liter, maximal dilation = 18 +/- 4%). In a 4,5-diaminofluorescein diacetate nitric oxide (NO) assay of isolated cortical arteries, AII stimulated NO production, which was abolished by PD123319, L-NA, or endothelial cell removal. Western immunoblot of arterial homogenates and endothelial and zona glomerulosa cell lysates revealed 48-kD and 50-kD bands corresponding to AT1 and AT2 receptors, respectively, in all three and a 140-kD band corresponding to endothelial NO synthase in endothelial cells and arteries. Our results demonstrate that AII stimulates adrenal cortical arterial dilation through endothelial cell AT2 receptor activation and NO release and AT1 receptor-dependent constriction.

Author List

Gauthier KM, Zhang DX, Edwards EM, Holmes B, Campbell WB

Authors

William B. Campbell PhD Chair, Professor in the Pharmacology and Toxicology department at Medical College of Wisconsin
David X. Zhang MD, PhD Associate Professor in the Medicine department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid
Adrenal Cortex
Angiotensin II
Animals
Arterioles
Cattle
Endothelium, Vascular
Losartan
Nitric Oxide
Nitric Oxide Donors
Nitroso Compounds
Vasoconstriction
Vasoconstrictor Agents
Vasodilator Agents
jenkins-FCD Prod-482 91ad8a360b6da540234915ea01ff80e38bfdb40a