Effect of vasoactive drugs on carotid diameter in humans

Istvan Bonyhay, Gabor Jokkel, Kristof Karlocai, Robert Reneman, M. Kollai

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

We studied whether vasoactive drugs used to determine baroreflex sensitivity influence baroreceptor firing by affecting carotid sinus smooth muscle or simply by stretching the sinus wall through changes in pressure. In six young healthy subjects, the diameter of the carotid artery and its change with arterial pulse were measured with ultrasonography. Blood pressure was measured by Finapres. Phenylephrine and nitroglycerin doses were rejected intravenously to raise and lower pressure by ~15-25 mmHg. Carotid dimensions increased in all subjects during the phenylephrine-induced rise and decreased during the nitroglycerin-induced fall in pressure. Diastolic diameter changed more than systolic diameter; changes were significantly different from the control value (assessed by single-factor analysis of variance and Scheffe's post hoc test). The systolic pressure-diameter relationship appeared to be nonlinear, with a steeper slope above than below baseline, and contributed significantly to the nonlinearity of the R-R interval-systolic pressure relationship. It is concluded that during drug-induced changes in blood pressure, baroreceptor activity in humans is influenced more by passive stretch than by local smooth muscle contraction.

Original languageEnglish
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume273
Issue number4 42-4
Publication statusPublished - 1997

Fingerprint

Blood Pressure
Pressoreceptors
Nitroglycerin
Phenylephrine
Pressure
Pharmaceutical Preparations
Smooth Muscle
Carotid Sinus
Baroreflex
Muscle Contraction
Carotid Arteries
Human Activities
Statistical Factor Analysis
Pulse
Ultrasonography
Analysis of Variance
Healthy Volunteers

Keywords

  • Baroreflex sensitivity
  • Carotid distensibility
  • Echo tracking
  • Nitroglycerin
  • Phenylephrine

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Cite this

Effect of vasoactive drugs on carotid diameter in humans. / Bonyhay, Istvan; Jokkel, Gabor; Karlocai, Kristof; Reneman, Robert; Kollai, M.

In: American Journal of Physiology - Heart and Circulatory Physiology, Vol. 273, No. 4 42-4, 1997.

Research output: Contribution to journalArticle

Bonyhay, Istvan ; Jokkel, Gabor ; Karlocai, Kristof ; Reneman, Robert ; Kollai, M. / Effect of vasoactive drugs on carotid diameter in humans. In: American Journal of Physiology - Heart and Circulatory Physiology. 1997 ; Vol. 273, No. 4 42-4.
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