Enhanced cardiopulmonary reflex inhibition of heart rate during exercise

Chao-Yin Chen, S. E. DiCarlo, H. L. Collins

Research output: Contribution to journalArticle

3 Scopus citations

Abstract

We tested the hypothesis that the reflex inhibition of heart rate (HR) during mechanical (acute bolus injection of 0.5% and 2% of estimated blood volume) and chemical (phenylbiguanide, PBG, 2.5 and 5 μg · kg-1) stimulation of cardiopulmonary receptors would be enhanced during exercise. Rats were instrumented with arterial and venous catheters. The reflex response to mechanical (N = 7) and chemical (N = 8) stimulation of cardiopulmonary receptors was examined at rest and during exercise (6 m · min-1, 10% grade). A two-way analysis of covariance (ANCOVA) with repeated measures was used to test for differences in the reflex regulation of HR at rest vs exercise. HR was used as the covariate bemuse exercise significantly increased baseline HR. There was no significant treatment effect (rest vs exercise) for the reflex inhibition of HR during mechanical stimulation. However, the two-way ANCOVA revealed a significant treatment effect (rest vs exercise) for the reflex inhibition of HR during chemical stimulation. The reflex decreases in HR were enhanced (-Δ 23 ± 8 vs -Δ 133 ± 47 and -Δ 208 ± 40 vs -Δ 374 ± 10 bpm at 2.5 and 5 μg · kg-1, respectively). These data suggest that factors associated with exercise enhanced the cardiopulmonary reflex inhibition of heart rate during chemical stimulation.

Original languageEnglish (US)
Pages (from-to)1399-1405
Number of pages7
JournalMedicine and Science in Sports and Exercise
Volume27
Issue number10
StatePublished - 1995
Externally publishedYes

Keywords

  • CHEMORECEPTORS
  • EXERCISE
  • MECHANORECEPTORS
  • VAGAL AFFERENTS

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine
  • Public Health, Environmental and Occupational Health
  • Physical Therapy, Sports Therapy and Rehabilitation

Fingerprint Dive into the research topics of 'Enhanced cardiopulmonary reflex inhibition of heart rate during exercise'. Together they form a unique fingerprint.

  • Cite this