Calibration of baroreflex equilibrium diagram based on exogenous pressor agents in chronic heart failure rats

Toru Kawada, Meihua Li, Yusuke Sata, Can Zheng, Michael J. Turner, Shuji Shimizu, Masaru Sugimachi

Research output: Contribution to journalArticleResearchpeer-review

3 Citations (Scopus)

Abstract

A baroreflex equilibrium diagram describes the relation between input pressure and sympathetic nerve activity (SNA) and that between SNA and arterial pressure (AP). To calibrate the SNA axis (abscissa) of the baroreflex equilibrium diagram, the AP response to intravenous bolus injec-tions of phenylephrine (0.2–50 μg/kg) or norepinephrine (NE, 0.02–5 μg/kg) was examined in normal control rats (NC, n = 9) and rats with chronic heart failure (CHF, n = 6). The maximum slope of the dose–effect curve was significantly smaller in the CHF group than in the NC group (57.3 ± 5.2 vs 80.9 ± 6.3 mmHg/decade for phenylephrine, 60.2 ± 7.8 vs 80.4 ± 5.9 mmHg/decade for NE; P , 0.01). The CHF/NC ratio of the maximum slope was used to calibrate SNA. While the calibrated baroreflex equilibrium diagram showed increased maximum SNA and operating-point SNA in CHF rats compared with NC rats, the magnitude of increase was smaller than that expected from the excess plasma NE concentration in CHF rats. Plasma NE concentration in the CHF group could be disproportionally high relative to SNA.

Original languageEnglish
Pages (from-to)1-9
Number of pages9
JournalClinical Medicine Insights: Cardiology
Volume9
Issue numberS1
DOIs
Publication statusPublished - 2015
Externally publishedYes

Keywords

  • Arterial pressure
  • Carotid sinus baroreflex
  • Norepinephrine
  • Open-loop analysis
  • Phenylephrine

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