Arterial and cardiopulmonary baroreflexes in 60- to 69- vs. 18- to 36- yr-old humans

Xiangrong Shi, Kevin M. Gallagher, Rita M. Welch-O'Connor, Brian H. Foresman

Research output: Contribution to journalArticlepeer-review

35 Scopus citations


This study was designed to test the hypothesis that aging diminished baroreflex function during central hypovolemia. Eleven healthy young and eleven older (age 60-69 yr) individuals were assessed by using heart rate (HR) and mean arterial pressure (MAP) responses to neck pressure and suction during rest and lower body negative pressure (LBNP) of -15 Torr. The slope of forearm vascular resistance to central venous pressure during low-level LBNP was assessed as the index of cardiopulmonary baroreflex sensitivity. Baseline cardiovascular variables were not significantly different between the groups. In addition, there was no group difference in cardiopulmonary baroreflex (- 3.6 vs. -3.7 units/mmHg for young vs. older, respectively) or carotid baroreflex (-0.39 vs. -0.35 beats-min-1 · mmHg-1 and -0.26 vs. -0.35 mmHg/mmHg, for young vs. older, respectively) sensitivity. LBNP did not affect either HR or MAP, whereas it decreased CVP and increased FVR in both groups. LBNP significantly augmented the carotid-HR (-0.47 ± 0.03 beats · min-1 · mmHg-1) and carotid-MAP (-0.42 ± 0.04 mmHg/mmHg) reflex gains in the young subjects only. We concluded that there was no difference in the discrete baroreflex function between the two age groups; however, the interaction of cardiopulmonary baroreceptors with carotid baroreflex function was absent in the older subjects, suggesting that the central integration of afferent neural inputs from the discrete baroreceptors was altered with aging.

Original languageEnglish
Pages (from-to)1903-1910
Number of pages8
JournalJournal of Applied Physiology
Issue number6
StatePublished - Jun 1996


  • aging
  • central hypovolemia
  • central venous pressure
  • forearm vascular resistance
  • gain
  • interaction
  • lower body negative pressure
  • peripheral venous pressure


Dive into the research topics of 'Arterial and cardiopulmonary baroreflexes in 60- to 69- vs. 18- to 36- yr-old humans'. Together they form a unique fingerprint.

Cite this