We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Low-Dose Angiotensin II Infusion Restores Vascular Function in Cerebral Arteries of High Salt–Fed Rats by Increasing Copper/Zinc Superoxide Dimutase Expression.
- Authors
Durand, Matthew J.; Lombard, Julian H.
- 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.
- Subjects
ANGIOTENSIN II; CEREBRAL arteries; SUPEROXIDE dismutase; MANGANESE; VASODILATORS; LABORATORY rats
- Publication
American Journal of Hypertension, 2013, Vol 26, Issue 6, p739
- ISSN
0895-7061
- Publication type
Article
- DOI
10.1093/ajh/hpt015