Faculty Collaboration Database

Low-dose angiotensin II infusion restores vascular function in cerebral arteries of high salt-fed rats by increasing copper/zinc superoxide dimutase expression. Am J Hypertens 2013 Jun;26(6):739-47

Date

02/28/2013

Pubmed ID

23443725

Pubmed Central ID

PMC3697069

DOI

10.1093/ajh/hpt015

Scopus ID

2-s2.0-84877785615 (requires institutional sign-in at Scopus site)   36 Citations

Abstract

BACKGROUND: This study examined the vasoprotective role of circulating angiotensin II (ANG II) levels in the cerebral circulation of high salt (HS)-fed (SS.BN-(D13hmgc41-13hmgc23)/Mcwi) (Ren1-BN) congenic rats, which carry a normally functioning renin allele from the Brown Norway (BN) rat on the Dahl salt-sensitive genetic background.

METHODS: Ren1-BN rats were placed on an HS (4.0% NaCl) diet for 3 days. The vasodilator response to acetylcholine (ACh; 10(-10) - 10(-6) mol/L) was assessed in isolated middle cerebral arteries (MCAs), and Western blots were performed to assess the expression of the antioxidant enzymes copper (Cu)/zinc (Zn) superoxide dismutase (SOD) and manganese (Mn) SOD in cerebral resistance vessels. A separate group of HS-fed animals were infused with either a subpressor dose of ANG II (100ng/kg/min) or saline vehicle via osmotic minipump for 3 days.

RESULTS: HS diet eliminated acetylcholine (ACh)-induced dilation in the MCAs of the congenic rats. Western blot analysis of antioxidant enzymes showed that Cu/Zn SOD and Mn SOD expression were significantly reduced in the cerebral resistance arteries of the HS-fed rats compared with control animals fed a normal salt diet. Infusion of ANG II restored the vasodilator response to ACh in the MCAs and increased Cu/Zn SOD (but not Mn SOD) expression compared with saline-infused animals.

CONCLUSIONS: These results indicate that prevention of salt-induced ANG II suppression prevents vascular dysfunction in the cerebral circulation by preventing the downregulation of Cu/Zn SOD and vascular oxidant stress that normally occurs with HS diet.

Author List

Durand MJ, Lombard JH

Author

Matt Durand PhD Associate Professor in the Physical Medicine and Rehabilitation department at Medical College of Wisconsin

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

Angiotensin II
Animals
Blood Pressure
Blotting, Western
Cerebral Arteries
Copper
Disease Models, Animal
Hypertension
Infusions, Intravenous
Male
Rats
Rats, Inbred BN
Recovery of Function
Superoxide Dismutase
Vasoconstrictor Agents
Vasodilation