| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Articles in PresS, published online ahead of print February 28, 2002
Am J Physiol Heart Circ Physiol, 10.1152/ajpheart.00038.2002
Submitted on January 20, 2002
Accepted on February 20, 2002
1 Cellular and Molecular Physiology, Pierce Laboratory/Yale University, New Haven, CT, USA
2 Human Physiology, Flinders University of S Australia, Adelaide, South Australia, Australia
* To whom correspondence should be addressed. E-mail: sssegal{at}jbpierce.org.
The conduction of vasodilation along resistance vessels has been presumed to reflect the electrotonic spread of hyperpolarization from cell-to-cell along the vessel wall through gap junction channels. However, the vasomotor response to acetylcholine (ACh) encompasses greater distances than can be explained by passive decay. To investigate the underlying mechanism for this behavior, we tested the hypothesis that ACh augments the conduction of hyperpolarization. Feed arteries (n = 23; diameter, 58 ± 4 µm; segment length, 2 - 8 mm) were isolated from the hamster retractor muscle, cannulated at each end, and pressurized to 75 mm Hg (at 37 °C). Vessels were impaled with 1 or 2 dye-containing microelectrodes simultaneously (separation distance, 50 µm - 3.5 mm). Membrane potential (Em; rest, ~ -30 mV) and electrical responses were similar between endothelium and smooth muscle, as predicted for robust myoendothelial coupling. Current injection (-0.8 nA, 1.5 s) evoked hyperpolarization (-10 ± 1 mV; membrane time constant, 240 ms) that conducted along the vessel with a length constant (
) = 1.2 ± 0.1 mm; spontaneous Em oscillations (~ 1 Hz) decayed with = 1.2 ± 0.1 mm. In contrast, ACh microiontophoresis (500 nA, 500 ms, 1 µm tip) evoked hyperpolarization (-14 ± 2 mV) that conducted with = 1.9 ± 0.1 µm, 60% further (P<0.05) than responses evoked by purely electrical stimuli. These findings indicate that ACh augments the conduction of hyperpolarization along the vessel wall.
This article has been cited by other articles:
|
|
 |
|
  X. F. Figueroa and B. R. Duling Dissection of two Cx37-independent conducted vasodilator mechanisms by deletion of Cx40: electrotonic versus regenerative conduction Am J Physiol Heart Circ Physiol, November 1, 2008; 295(5): H2001 - H2007. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
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]
|
|
|
|
 |
|
 M. L. Paffett, J. S. Naik, T. C. Resta, and B. R. Walker Reduced store-operated Ca2+ entry in pulmonary endothelial cells from chronically hypoxic rats Am J Physiol Lung Cell Mol Physiol, November 1, 2007; 293(5): L1135 - L1142. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X. F. Figueroa, C.-C. Chen, K. P. Campbell, D. N. Damon, K. H. Day, S. Ramos, and B. R. Duling Are voltage-dependent ion channels involved in the endothelial cell control of vasomotor tone? Am J Physiol Heart Circ Physiol, September 1, 2007; 293(3): H1371 - H1383. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. D. Frame, R. J. Rivers, O. Altland, and S. Cameron Mechanisms initiating integrin-stimulated flow recruitment in arteriolar networks J Appl Physiol, June 1, 2007; 102(6): 2279 - 2287. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. R. Uhrenholt, T. L. Domeier, and S. S. Segal Propagation of calcium waves along endothelium of hamster feed arteries Am J Physiol Heart Circ Physiol, March 1, 2007; 292(3): H1634 - H1640. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. L. Domeier and S. S. Segal Electromechanical and pharmacomechanical signalling pathways for conducted vasodilatation along endothelium of hamster feed arteries J. Physiol., February 15, 2007; 579(1): 175 - 186. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. C. Ngai, T.-S. Nguyen, J. R. Meno, and G. W. Britz Postischemic Augmentation of Conducted Dilation in Cerebral Arterioles Stroke, January 1, 2007; 38(1): 124 - 130. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. C. Jantzi, S. E. Brett, W. F. Jackson, R. Corteling, E. J. Vigmond, and D. G. Welsh Inward rectifying potassium channels facilitate cell-to-cell communication in hamster retractor muscle feed arteries Am J Physiol Heart Circ Physiol, September 1, 2006; 291(3): H1319 - H1328. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Thengchaisri and R. J. Rivers Remote arteriolar dilations caused by methacholine: a role for CGRP sensory nerves? Am J Physiol Heart Circ Physiol, August 1, 2005; 289(2): H608 - H613. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Earley, T. C. Resta, and B. R. Walker Disruption of smooth muscle gap junctions attenuates myogenic vasoconstriction of mesenteric resistance arteries Am J Physiol Heart Circ Physiol, December 1, 2004; 287(6): H2677 - H2686. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. J Haug, D. G Welsh, and S. S Segal Sympathetic Nerves Inhibit Conducted Vasodilatation Along Feed Arteries during Passive Stretch of Hamster Skeletal Muscle J. Physiol., October 1, 2003; 552(1): 273 - 282. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Budel, I. S. Bartlett, and S. S. Segal Homocellular Conduction Along Endothelium and Smooth Muscle of Arterioles in Hamster Cheek Pouch: Unmasking an NO Wave Circ. Res., July 11, 2003; 93(1): 61 - 68. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Tyml, D. Anderson, D. Lidington, and H. M. Ladak A new method for assessing arteriolar diameter and hemodynamic resistance using image analysis of vessel lumen Am J Physiol Heart Circ Physiol, May 1, 2003; 284(5): H1721 - H1728. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
