| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Research Service, Veterans Affairs Medical Center and Department of Internal Medicine, University of Iowa, Iowa City, Iowa 52242
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.
angiotensin-converting enzyme; captopril; circumventricular organs; anesthetized rat; angiotensin I
This article has been cited by other articles:
|
|
 |
|
  S.-G. Wei, Y. Yu, Z.-H. Zhang, R. M. Weiss, and R. B. Felder Angiotensin II-Triggered p44/42 Mitogen-Activated Protein Kinase Mediates Sympathetic Excitation in Heart Failure Rats Hypertension, August 1, 2008; 52(2): 342 - 350. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Francis, S.-G. Wei, R. M. Weiss, and R. B. Felder Brain angiotensin-converting enzyme activity and autonomic regulation in heart failure Am J Physiol Heart Circ Physiol, November 1, 2004; 287(5): H2138 - H2146. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z.-H. Zhang and R. B. Felder Melanocortin receptors mediate the excitatory effects of blood-borne murine leptin on hypothalamic paraventricular neurons in rat Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2004; 286(2): R303 - R310. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Q. H. Chen and G. M. Toney Responses to GABA-A receptor blockade in the hypothalamic PVN are attenuated by local AT1 receptor antagonism Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2003; 285(5): R1231 - R1239. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z.-H. Zhang, S.-G. Wei, J. Francis, and R. B. Felder Cardiovascular and renal sympathetic activation by blood-borne TNF-alpha in rat: the role of central prostaglandins Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2003; 284(4): R916 - R927. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. B. Felder, J. Francis, Z.-H. Zhang, S.-G. Wei, R. M. Weiss, and A. K. Johnson Heart failure and the brain: new perspectives Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2003; 284(2): R259 - R276. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z.-H. Zhang, J. Francis, R. M. Weiss, and R. B. Felder The renin-angiotensin-aldosterone system excites hypothalamic paraventricular nucleus neurons in heart failure Am J Physiol Heart Circ Physiol, July 1, 2002; 283(1): H423 - H433. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Francis, S.-G. Wei, R. M. Weiss, T. Beltz, A. K. Johnson, and R. B. Felder Forebrain-mediated adaptations to myocardial infarction in the rat Am J Physiol Heart Circ Physiol, May 1, 2002; 282(5): H1898 - H1906. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
