Open AccessAbsence of Flow-Mediated Vasodilation in the Rabbit Femoral Artery
Author(s) -
Philip S. Clifford,
Jane A. Madden,
Jason J. Hamann,
John B. Buckwalter,
Zoran Valić
Publication year - 2010
Publication title -
physiological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.647
H-Index - 70
eISSN - 1802-9973
pISSN - 0862-8408
DOI - 10.33549/physiolres.931672
Subject(s) - vasodilation , femoral artery , constriction , phenylephrine , blood flow , artery , medicine , chemistry , endothelium , anatomy , hemodynamics , anesthesia , cardiology , blood pressure
The purpose of this study was to determine if there is flowmediated vasodilation of the femoral artery in response to progressive increases in flow within a physiological rangeobserved in the in vivo experiments. Femoral artery blood flowwas determined in conscious rabbits (n=5) using chronicallyimplanted flowprobes. Resting blood flow was 8.3±0.6 ml/minand increased to 39.9±5.4 ml/min during high intensity exercise.Femoral arteries (n=12, 1705±43 µm outer diameter) harvestedfrom a separate group of rabbits were mounted on cannulas anddiameter was continuously monitored by video system.Functional integrity of the endothelium was tested withacetylcholine. The arteries were set at a transmural pressure of100 mm Hg and preconstricted with phenylephrine to 73±3 % ofinitial diameter. Using a roller pump with pressure held constant,the arteries were perfused intraluminally with warmed,oxygenated Krebs' solution (pH=7.4) over a physiological rangeof flows up to 35 ml/min. As flow increased from 5 ml/min to35 ml/min, diameter decreased significantly (p<0.05) from1285±58 µm to 1100±49 µm. Thus, in vessels with a functionalendothelium, increasing intraluminal flow over a physiologicalrange of flows produced constriction, not dilation. Based on theseresults, it seems unlikely that flow-mediated vasodilation in therabbit femoral artery contributes to exercise hyperemia.