Faculty Collaboration Database

Reduced angiotensin II levels cause generalized vascular dysfunction via oxidant stress in hamster cheek pouch arterioles. Microvasc Res 2013 Sep;89:134-45

Date

05/01/2013

Pubmed ID

23628292

Pubmed Central ID

PMC3758804

DOI

10.1016/j.mvr.2013.04.004

Scopus ID

2-s2.0-84883204346 (requires institutional sign-in at Scopus site)   21 Citations

Abstract

OBJECTIVES: We investigated the effect of suppressing plasma angiotensin II (ANG II) levels on arteriolar relaxation in the hamster cheek pouch.

METHODS: Arteriolar diameters were measured via television microscopy during short-term (3-6days) high salt (HS; 4% NaCl) diet and angiotensin converting enzyme (ACE) inhibition with captopril (100mg/kg/day).

RESULTS: ACE inhibition and/or HS diet eliminated endothelium-dependent arteriolar dilation to acetylcholine, endothelium-independent dilation to the NO donor sodium nitroprusside, the prostacyclin analogs carbacyclin and iloprost, and the KATP channel opener cromakalim; and eliminated arteriolar constriction during KATP channel blockade with glibenclamide. Scavenging of superoxide radicals and low dose ANG II infusion (25ng/kg/min, subcutaneous) reduced oxidant stress and restored arteriolar dilation in arterioles of HS-fed hamsters. Vasoconstriction to topically-applied ANG II was unaffected by HS diet while arteriolar responses to elevation of superfusion solution PO2 were unaffected (5% O2, 10% O2) or reduced (21% O2) by HS diet.

CONCLUSIONS: These findings indicate that sustained exposure to low levels of circulating ANG II leads to widespread dysfunction in endothelium-dependent and independent vascular relaxation mechanisms in cheek pouch arterioles by increasing vascular oxidant stress, but does not potentiate O2- or ANG II-induced constriction of arterioles in the distal microcirculation of normotensive hamsters.

Author List

Priestley JR, Buelow MW, McEwen ST, Weinberg BD, Delaney M, Balus SF, Hoeppner C, Dondlinger L, Lombard JH

Author

Matthew W. Buelow MD Associate Professor in the Pediatrics department at Medical College of Wisconsin

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

Acetylcholine
Angiotensin II
Animals
Arterioles
Blood Pressure
Captopril
Cheek
Cricetinae
Cromakalim
Endothelium, Vascular
Epoprostenol
Glyburide
Iloprost
Male
Mesocricetus
Microscopy
Microscopy, Video
Nitroprusside
Oxidants
Oxygen
Peptidyl-Dipeptidase A
Superoxides
Vascular Diseases