Published Online
on January 15, 2007

A more recent version of this article appeared on March 1, 2007

This Article Full Text (PDF) All Versions of this Article: 49/3/519    most recent 01.HYP.0000256955.74461.93v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Pan, Y.-X. Articles by Wang, W. Search for Related Content PubMed PubMed Citation Articles by Pan, Y.-X. Articles by Wang, W. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Medline Plus Health Information Autonomic Nervous System Disorders Related Collections ACE/Angiotension receptors Exercise/exercise testing/rehabilitation Autonomic, reflex, and neurohumoral control of circulation Oxidant stress

Submitted on July 25, 2006
Revised on August 14, 2006

Exercise Training Prevents Arterial Baroreflex Dysfunction in Rats Treated With Central Angiotensin II

Yan-Xia Pan; Lie Gao; Wei-Zhong Wang; Hong Zheng; Dongmei Liu; Kaushik P. Patel; Irving H. Zucker; and Wei Wang^*

From the Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha.

^* To whom correspondence should be addressed. E-mail: weiwang{at}unmc.edu.

Abstract--Angiotensin II (Ang II)-induced arterial baroreflex dysfunction is associated with superoxide generation in the brain. Exercise training (EX) improves baroreflex function and decreases oxidative stress in cardiovascular diseases linked to elevated central Ang II. The aim of this study was to determine whether previous EX prevents baroreflex impairment caused by central administration of exogenous Ang II via an Ang II-superoxide mechanism. Four groups of rats were used: non-EX artificial cerebrospinal fluid infused, non-EX Ang II infused, EX artificial cerebrospinal fluid infused, and EX Ang II infused. Rats were treadmill trained for 3 to 4 weeks and subjected to intracerebroventricular infusion of Ang II over the last 3 days of EX. Twenty-four hours after the end of EX, the arterial baroreflex was assessed in anesthetized rats. Compared with non-EX artificial cerebrospinal fluid-infused rats, Ang II significantly decreased baroreflex sensitivity (maximum gain: 3.0±0.2% of maximum per millimeter of mercury versus 1.6±0.1% of maximum per millimeter of mercury; P<0.01), which was abolished by acute intracerebroventricular infusion of the Ang II type 1 receptor antagonist losartan and the reduced nicotinamide-adenine dinucleotide phosphate oxidase inhibitor apocynin. EX prevented the decrease in baroreflex sensitivity and downregulated Ang II type 1 receptor and NADPH oxidase subunit protein expression in the paraventricular nucleus of Ang II-infused rats. Finally, EX decreased superoxide production in the paraventricular nucleus of Ang II-infused rats. These results indicate that EX improves arterial baroreflex function in conditions of high brain Ang II, which is mediated by the central Ang II type 1 receptor and associated with a reduction in central oxidative stress.

Key words: exercise • baroreflex • sympathetic nerve activity • reactive oxygen species • AT₁ receptor

This article has been cited by other articles:

				H. Zheng, Y.-F. Li, W. Wang, and K. P. Patel Enhanced angiotensin-mediated excitation of renal sympathetic nerve activity within the paraventricular nucleus of anesthetized rats with heart failure Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2009; 297(5): R1364 - R1374. [Abstract] [Full Text] [PDF]

				I. H. Zucker, H. D. Schultz, K. P. Patel, W. Wang, and L. Gao Regulation of central angiotensin type 1 receptors and sympathetic outflow in heart failure Am J Physiol Heart Circ Physiol, November 1, 2009; 297(5): H1557 - H1566. [Abstract] [Full Text] [PDF]

				Z.-H. Zhang, Y. Yu, Y.-M. Kang, S.-G. Wei, and R. B. Felder Aldosterone acts centrally to increase brain renin-angiotensin system activity and oxidative stress in normal rats Am J Physiol Heart Circ Physiol, February 1, 2008; 294(2): H1067 - H1074. [Abstract] [Full Text] [PDF]

				T. M. Paravicini and R. M. Touyz NADPH Oxidases, Reactive Oxygen Species, and Hypertension: Clinical implications and therapeutic possibilities Diabetes Care, February 1, 2008; 31(Supplement_2): S170 - S180. [Abstract] [Full Text] [PDF]