This Article Full Text Full Text (PDF) All Versions of this Article: 40/3/335    most recent 01.HYP.0000029241.33421.EBv1 Alert me when this article is cited Alert me if a correction is posted Citation Map 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 Chan, J. Y.H. Articles by Chan, S. H.H. Search for Related Content PubMed PubMed Citation Articles by Chan, J. Y.H. Articles by Chan, S. H.H. Pubmed/NCBI databases Gene GEO Profiles HomoloGene UniGene Compound via MeSH Substance via MeSH Medline Plus Health Information High Blood Pressure Related Collections Autonomic, reflex, and neurohumoral control of circulation ACE/Angiotension receptors Gene regulation

(Hypertension. 2002;40:335.)
© 2002 American Heart Association, Inc.

Scientific Contributions

Augmented Upregulation by c-fos of Angiotensin Subtype 1 Receptor in Nucleus Tractus Solitarii of Spontaneously Hypertensive Rats

From the Department of Medical Education and Research, Kaohsiung Veterans General Hospital (J.Y.H.C., L.W., H.L.), Kaohsiung, Taiwan, Republic of China; and Center for Neuroscience, National Sun Yat-sen University (S.H.H.C.), Kaohsiung, Taiwan, Republic of China.

Correspondence to Samuel H.H. Chan, PhD, Center for Neuroscience, National Sun Yat-sen University, Kaohsiung 804, Taiwan, Republic of China. E-mail schan{at}mail.nsysu.edu.tw

Our laboratory demonstrated previously that spontaneously hypertensive rats (SHR) exhibited an elevated basal Fos expression in the nucleus tractus solitarii (NTS), the terminal site for primary baroreceptor afferents, and that Fos protein is required for the re-expression of angiotensin subtype 1 receptor (AT1R) mRNA in the NTS after baroreceptor activation. The present study evaluated the hypothesis that this re-expression of AT1R is augmented in SHR and is promoted by the heightened Fos expression. Reverse transcription–polymerase chain reaction analysis revealed that baroreceptor activation via sustained increase in systemic arterial pressure resulted in a discernible reduction in the expression of AT1R mRNA at the dorsomedial medulla of SHR and normotensive Wistar-Kyoto rats. However, SHR manifested an appreciably larger magnitude of decline, followed by a faster time course of re-expression in AT1R mRNA. Parallel findings were obtained from the pressor response induced by microinjection unilaterally of angiotensin II (40 pmol) into the NTS. Whereas the re-expression of AT1R at both transcriptional and functional expression levels after baroreceptor activation was discernibly blunted by prior bilateral application into the NTS of an antisense c-fos oligonucleotide (50 pmol), the suppression in SHR was again significantly more intense. Control pretreatment with the corresponding sense or scrambled c-fos oligonucleotide was ineffective. We conclude that the heightened Fos expression in SHR is causatively related to the augmented re-expression of AT1R in the NTS at both transcriptional and functional levels.

Key Words: receptors, angiotensin • Fos protein • nucleus tractus solitarii • transcription • hypertension, genetic • rats

This article has been cited by other articles:

				D. Liu, L. Gao, S. K. Roy, K. G. Cornish, and I. H. Zucker Role of Oxidant Stress on AT1 Receptor Expression in Neurons of Rabbits With Heart Failure and in Cultured Neurons Circ. Res., July 18, 2008; 103(2): 186 - 193. [Abstract] [Full Text] [PDF]

				J. T. Cunningham, M. Herrera-Rosales, M. A. Martinez, and S. Mifflin Identification of Active Central Nervous System Sites in Renal Wrap Hypertensive Rats Hypertension, March 1, 2007; 49(3): 653 - 658. [Abstract] [Full Text] [PDF]

				I. H. Zucker Novel Mechanisms of Sympathetic Regulation in Chronic Heart Failure Hypertension, December 1, 2006; 48(6): 1005 - 1011. [Full Text] [PDF]

				S. H. H. Chan, K.-F. Chang, C.-C. Ou, and J. Y. H. Chan Nitric Oxide Regulates c-fos Expression in Nucleus Tractus Solitarii Induced by Baroreceptor Activation via cGMP-Dependent Protein Kinase and cAMP Response Element-Binding Protein Phosphorylation Mol. Pharmacol., February 1, 2004; 65(2): 319 - 325. [Abstract] [Full Text] [PDF]

				J. Y.H. Chan, L.-L. Wang, C.-C. Ou, and S. H.H. Chan Downregulation of Angiotensin Subtype 1 Receptor in Rostral Ventrolateral Medulla During Endotoxemia Hypertension, July 1, 2003; 42(1): 103 - 109. [Abstract] [Full Text] [PDF]