| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Medicine, University of California San Diego, La Jolla, CA, USA
* To whom correspondence should be addressed. E-mail: dwray{at}ucsd.edu.
Arm and leg vascular responsiveness to comparable shear stimuli during isolated dynamic exercise has not been assessed in humans. Consequently, six young cyclists performed incremental, intermittent handgrip exercise (arm) and knee-extensor exercise (leg) from 5-60% of maximal work rate (WR). Ultrasound Doppler measurements were taken in the brachial artery (BA), common femoral artery (CFA), and deep femoral artery (DFA) at rest and at each WR to assess diameter and sheer rate changes. Exercise at WR60%max increased shear rate to the same degree in the CFA (314.3 ± 33.3s-1) and BA (303.3 ± 26.3s-1), but was significantly higher in the DFA (712.6 ± 88.3s-1). Compared to rest, exercise at WR60%max did not alter CFA vessel diameter, but increased BA diameter (0.42 ± 0.01 to 0.49 ± 0.01 cm) and DFA diameter (0.59 ± 0.05 to 0.64 ± 0.04 cm). These data from the DFA demonstrate for the first time a substantial improvement in vascular reactivity in a conduit vessel only slightly distal to the CFA. However, despite comparable dilation between the BA and DFA, the slope of the relationship between vessel diameter and shear rate was much greater in the arm (2.4E-4 ± 4.6E-5 cm/s-1) than in either the DFA (8.9E-5 ± 1.5E-5 cm/s-1) or CFA (2.1E-5 ± 1.1E-5 cm/s-1). Together, these findings reveal a substantial heterogeneity in vascular responsiveness in the leg during dynamic exercise, but demonstrate that conduit vessel dilation for a given change in shear rate is nonetheless reduced in the leg compared with the arm.
This article has been cited by other articles:
|
|
 |
|
  K. E. Pyke, V. Poitras, and M. E. Tschakovsky Brachial artery flow-mediated dilation during handgrip exercise: evidence for endothelial transduction of the mean shear stimulus Am J Physiol Heart Circ Physiol, June 1, 2008; 294(6): H2669 - H2679. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. W. Wray, S. K. Nishiyama, R. A. Harris, and R. S. Richardson Angiotensin II in the Elderly: Impact of Angiotensin II Type 1 Receptor Sensitivity on Peripheral Hemodynamics Hypertension, June 1, 2008; 51(6): 1611 - 1616. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. H. J. Thijssen, M. Kooijman, P. C. E. de Groot, M. W. P. Bleeker, P. Smits, D. J. Green, and M. T. E. Hopman Endothelium-dependent and -independent vasodilation of the superficial femoral artery in spinal cord-injured subjects J Appl Physiol, May 1, 2008; 104(5): 1387 - 1393. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Kooijman, D. H. J. Thijssen, P. C. E. de Groot, M. W. P. Bleeker, H. J. M. van Kuppevelt, D. J. Green, G. A. Rongen, P. Smits, and M. T. E. Hopman Flow-mediated dilatation in the superficial femoral artery is nitric oxide mediated in humans J. Physiol., February 15, 2008; 586(4): 1137 - 1145. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. W. Wray, S. K. Nishiyama, A. J. Donato, M. Sander, P. D. Wagner, and R. S. Richardson Endothelin-1-mediated vasoconstriction at rest and during dynamic exercise in healthy humans Am J Physiol Heart Circ Physiol, October 1, 2007; 293(4): H2550 - H2556. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. K. Nishiyama, D. Walter Wray, K. Berkstresser, M. Ramaswamy, and R. S. Richardson Limb-specific differences in flow-mediated dilation: the role of shear rate J Appl Physiol, September 1, 2007; 103(3): 843 - 851. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. K. Pellinger and J. R. Halliwill Effect of propranolol on sympathetically mediated leg vasoconstriction in humans J. Physiol., September 1, 2007; 583(2): 797 - 809. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. W. Wray, A. J. Donato, S. K. Nishiyama, and R. S. Richardson Acute sympathetic vasoconstriction at rest and during dynamic exercise in cyclists and sedentary humans J Appl Physiol, February 1, 2007; 102(2): 704 - 712. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. A. Parker, S. J. Ridout, and D. N. Proctor Age and flow-mediated dilation: a comparison of dilatory responsiveness in the brachial and popliteal arteries Am J Physiol Heart Circ Physiol, December 1, 2006; 291(6): H3043 - H3049. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. W. Wray, A. Uberoi, L. Lawrenson, and R. S. Richardson Evidence of preserved endothelial function and vascular plasticity with age Am J Physiol Heart Circ Physiol, March 1, 2006; 290(3): H1271 - H1277. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. J. Donato, A. Uberoi, D. W. Wray, S. Nishiyama, L. Lawrenson, and R. S. Richardson Differential effects of aging on limb blood flow in humans Am J Physiol Heart Circ Physiol, January 1, 2006; 290(1): H272 - H278. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
