ANG II in the paraventricular nucleus potentiates the cardiac sympathetic afferent reflex in rats with heart failure

Guo Qing Zhu, Lie Gao, Kuashik P. Patel, Irving H. Zucker, Wei Wang

Research output: Contribution to journalArticle

72 Scopus citations

Abstract

Chronic heart failure (CHF) is characterized by sympathoexcitation, and the cardiac sympathetic afferent reflex (CSAR) is a sympathoexcitatory reflex. Our previous studies have shown that the CSAR was enhanced in CHF. In addition, central angiotensin II (ANG II) is an important modulator of this reflex. This study was performed to determine whether the CSAR evoked by stimulation of cardiac sympathetic afferent nerves (CSAN) in rats with coronary ligation-induced CHF is enhanced by ANG II in the paraventricular nucleus (PVN). Under α-chloralose and urethane anesthesia, renal sympathetic nerve activity (RSNA) was recorded. The RSNA responses to electrical stimulation (5, 10, 20, and 30 Hz) of the CSAN were evaluated. Bilateral microinjection of the AT1-receptor antagonist losartan (50 nmol) into the PVN had no significant effects in the sham group, but it abolished the enhanced RSNA response to stimulation in the CHF group. Unilateral microinjection of three doses of ANG II (0.03, 0.3, and 3 nmol) into the PVN resulted in dose-related increases in the RSNA responses to stimulation. Although ANG II also potentiated the RSNA response to electrical stimulation in sham rats, the RSNA responses to stimulation after ANG II into the PVN in rats with CHF were much greater than in sham rats. The effects of ANG II were prevented by pretreatment with losartan into the PVN in CHF rats. These results suggest that the central gain of the CSAR is enhanced in rats with coronary ligation-induced CHF and that ANG II in the PVN augments the CSAR evoked by CSAN, which is mediated by the central angiotensin AT1 receptors in rats with CHF.

Original languageEnglish (US)
Pages (from-to)1746-1754
Number of pages9
JournalJournal of Applied Physiology
Volume97
Issue number5
DOIs
StatePublished - Nov 2004

Keywords

  • Angiotensin AT
  • Angiotensin II
  • Cardiac sympathetic afferent reflex
  • Chronic heart failure
  • Paraventricular nucleus
  • Receptor
  • Renal sympathetic nerve activity

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Fingerprint Dive into the research topics of 'ANG II in the paraventricular nucleus potentiates the cardiac sympathetic afferent reflex in rats with heart failure'. Together they form a unique fingerprint.

  • Cite this