Journal article
Forebrain renin-angiotensin system has a tonic excitatory influence on renal sympathetic nerve activity
American journal of physiology. Heart and circulatory physiology, Vol.282(3), pp.H890-H895
03/01/2002
DOI: 10.1152/ajpheart.2002.282.3.H890
PMID: 11834483
Abstract
All elements of the renin-angiotensin system (RAS) are present in the forebrain, particularly in circumventricular organs surrounding the third cerebral ventricle. We tested the hypothesis that forebrain angiotensin-converting enzyme (ACE) has a tonic excitatory influence on sympathetic drive. Neurally intact and sinoaortic-denervated pentobarbital-anesthetized rats were treated with forebrain-directed intracarotid artery (ICA) versus intravenous injections of angiotensin I (ANG I) and of the ACE inhibitor captopril. In intact rats, ICA ANG I elicited a rise in arterial pressure and a concomitant reduction in renal sympathetic nerve activity (RSNA; ICA captopril elicited the opposite responses). In barodenervated rats, ICA ANG I increased and ICA captopril decreased arterial pressure and RSNA in parallel; intravenous ANG I had no effect on RSNA. The findings suggest that the intrinsic forebrain RAS has a tonic excitatory influence on sympathetic drive that is overshadowed in normal rats by baroreflex mechanisms, but may assume a more prominent role in pathophysiological states (e.g., heart failure) in which baroreflex mechanisms are impaired and RAS activity is augmented.
Details
- Title: Subtitle
- Forebrain renin-angiotensin system has a tonic excitatory influence on renal sympathetic nerve activity
- Creators
- Shun-Guang Wei - Research Service, Veterans Affairs Medical Center and Department of Internal Medicine, University of Iowa, Iowa City, Iowa 52242Robert B Felder - Research Service, Veterans Affairs Medical Center and Department of Internal Medicine, University of Iowa, Iowa City, Iowa 52242
- Resource Type
- Journal article
- Publication Details
- American journal of physiology. Heart and circulatory physiology, Vol.282(3), pp.H890-H895
- DOI
- 10.1152/ajpheart.2002.282.3.H890
- PMID
- 11834483
- ISSN
- 0363-6135
- eISSN
- 1522-1539
- Language
- English
- Date published
- 03/01/2002
- Academic Unit
- Iowa Neuroscience Institute; Cardiovascular Medicine; Internal Medicine
- Record Identifier
- 9984065377602771
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