| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi 39216-4505
Muscle blood flow is regulated to meet the metabolic needs of the tissue. With the vasculature arranged as a successive branching of arterioles and the larger, >50 µm, arterioles providing the major site of resistance, an increasing metabolic demand requires the vasodilation of the small arterioles first then the vasodilation of the more proximal, larger arterioles. The mechanism(s) for the coordination of this ascending vasodilation are not clear and may involve a conducted vasodilation and/or a flow-dependent response. The close arteriolar-venular pairing provides an additional mechanism by which the arteriolar diameter can be increased due to the diffusion of vasoactive substances from the venous blood. Evidence is presented that the venular endothelium releases a relaxing factor, a metabolite of arachidonic acid, that will vasodilate the adjacent arteriole. The stimulus for this release is not known, but it is hypothesized that hypoxia-induced ATP release from red blood cells may be responsible for the stimulation of arachidonic release from the venular endothelial cells. Thus the venous circulation is in an optimal position to monitor the overall metabolic state of the tissue and thus provide a feedback regulation of arteriolar diameter.
vasodilation; venular endothelium; relaxing factor
This article has been cited by other articles:
|
|
 |
|
  J. C. Arciero, B. E. Carlson, and T. W. Secomb Theoretical model of metabolic blood flow regulation: roles of ATP release by red blood cells and conducted responses Am J Physiol Heart Circ Physiol, October 1, 2008; 295(4): H1562 - H1571. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. P. Bochmann, W. Seibel, E. Haase, V. Hietschold, H. Rodel, and A. Deussen External compression increases forearm perfusion J Appl Physiol, December 1, 2005; 99(6): 2337 - 2344. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. G. Schrage, B. W. Wilkins, V. L. Dean, J. P. Scott, N. K. Henry, M. E. Wylam, and M. J. Joyner Exercise hyperemia and vasoconstrictor responses in humans with cystic fibrosis J Appl Physiol, November 1, 2005; 99(5): 1866 - 1871. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Alomari, A. Solomito, R. Reyes, S. M. Khalil, R. H. Wood, and M. A. Welsch Measurements of vascular function using strain-gauge plethysmography: technical considerations, standardization, and physiological findings Am J Physiol Heart Circ Physiol, January 1, 2004; 286(1): H99 - H107. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Saltzman, A. Toth, A. G. Tsai, M. Intaglietta, and P. C. Johnson Oxygen tension distribution in postcapillary venules in resting skeletal muscle Am J Physiol Heart Circ Physiol, November 1, 2003; 285(5): H1980 - H1985. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. R. Pries, B. Reglin, and T. W. Secomb Structural response of microcirculatory networks to changes in demand: information transfer by shear stress Am J Physiol Heart Circ Physiol, June 1, 2003; 284(6): H2204 - H2212. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. R. Harris Arteriovenous Pairing: a Determinant of Capillary Exchange Physiology, April 1, 2003; 18(2): 83 - 87. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
