| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Medicine, University of California San Diego, La Jolla, California, United States
2 Department of Medicine, University of California San Diego, 92093, California, United States
3 Department of Medicine, University of California San Diego, La Jolla, California, United States; Department of Medicine and Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah, United States
* To whom correspondence should be addressed. E-mail: rrichardson{at}ucsd.edu.
We sought to examine flow-mediated vasodilation (FMD) in both the arm (brachial artery, BA) and lower leg (popliteal artery, PA) of 13 young, healthy subjects. Vessel diameter, blood velocity, and calculated shear rate were determined with ultrasound Doppler following a traditional (5 min) suprasystolic cuff occlusion in both the BA and PA and an additional reduced occlusion period (30-120 s) in the BA to more closely equate the shear stimulus observed in the PA. The BA revealed a smaller diameter and larger post-ischemic cumulative blood velocity (area under curve, AUC) than the PA, a combination that resulted in an elevated post-cuff cumulative shear rate (AUC) in the BA (BA: 25419 ± 2896 s-1·s; PA 8089 ± 1048 s-1·s, P 
0.05). Thus, when expressed in traditional terms there was a tendency for the BA to have a greater FMD than the PA (6.5 ± 1.0% and 4.5 ± 0.8%, respectively; P = 0.1). However, when shear rate was experimentally matched (PA: 4.5 ± 0.8%; BA: -0.4 ± 0.4%) or mathematically normalized; (PA: 6.8x10-4 ± 1.6x10-4 %
/ s-1·s; BA: 2.5x10-4 ± 0.4x10-4 %/ s-1·s) the PA revealed a greater FMD per unit of shear rate than the BA (P 0.05). These data highlight the importance of assessing the shear stimulus to which each vessel is exposed and reveal limb-specific differences in flow-mediated dilation.
This article has been cited by other articles:
|
|
 |
|
  B. A. Parker, T. L. Trehearn, and J. R. Meendering Pick your Poiseuille: normalizing the shear stimulus in studies of flow-mediated dilation J Appl Physiol, October 1, 2009; 107(4): 1357 - 1359. [Full Text] [PDF]
|
|
|
|
|
|
B. J. Wong, G. Simmons, C. Bopp, J. Yeboah, D. P. Casey, C. Austin, H. Tanaka, A. E. DeVan, J. N. Barnes, G. Atkinson, et al. Commentaries on Viewpoint: Pick your Poiseuille: Normalizing the shear stimulus in studies of flow-mediated dilation J Appl Physiol, October 1, 2009; 107(4): 1360 - 1365. [Full Text] [PDF]
|
|
|
|
 |
|
 J. Padilla, R. D. Sheldon, D. M. Sitar, and S. C. Newcomer Impact of acute exposure to increased hydrostatic pressure and reduced shear rate on conduit artery endothelial function: a limb-specific response Am J Physiol Heart Circ Physiol, September 1, 2009; 297(3): H1103 - H1108. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. W. Wray, S. K. Nishiyama, and R. S. Richardson Role of {alpha}1-adrenergic vasoconstriction in the regulation of skeletal muscle blood flow with advancing age Am J Physiol Heart Circ Physiol, February 1, 2009; 296(2): H497 - H504. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. H. J. Thijssen, L. M. Bullens, M. M. van Bemmel, E. A. Dawson, N. Hopkins, T. M. Tinken, M. A. Black, M. T. E. Hopman, N. T. Cable, and D. J. Green Does arterial shear explain the magnitude of flow-mediated dilation?: a comparison between young and older humans Am J Physiol Heart Circ Physiol, January 1, 2009; 296(1): H57 - H64. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. K. Nishiyama, D. W. Wray, and R. S. Richardson Aging affects vascular structure and function in a limb-specific manner J Appl Physiol, November 1, 2008; 105(5): 1661 - 1670. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. H. J. Thijssen, E. A. Dawson, M. A. Black, M. T. E. Hopman, N. T. Cable, and D. J. Green Heterogeneity in conduit artery function in humans: impact of arterial size Am J Physiol Heart Circ Physiol, November 1, 2008; 295(5): H1927 - H1934. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. H. J. Thijssen, M. M. van Bemmel, L. M. Bullens, E. A. Dawson, N. D. Hopkins, T. M. Tinken, M. A. Black, M. T. E. Hopman, N. T. Cable, and D. J. Green The impact of baseline diameter on flow-mediated dilation differs in young and older humans Am J Physiol Heart Circ Physiol, October 1, 2008; 295(4): H1594 - H1598. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. K. Nishiyama, D. W. Wray, and R. S. Richardson Sex and limb-specific ischemic reperfusion and vascular reactivity Am J Physiol Heart Circ Physiol, September 1, 2008; 295(3): H1100 - H1108. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. C. Newcomer, C. L. Sauder, N. T. Kuipers, M. H. Laughlin, and C. A. Ray Effects of posture on shear rates in human brachial and superficial femoral arteries Am J Physiol Heart Circ Physiol, April 1, 2008; 294(4): H1833 - H1839. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
