|
|
||||||||
Department of Anesthesiology, Baylor College of Medicine, Houston, Texas 77030
Inward rectifier K+ channels (Kirs) were studied in the isolated perfused rat middle cerebral artery (MCA). The addition of 15 mM K+ (KCl) to the extraluminal bath dilated the MCAs. These dilations were blocked by selective inhibitors for the Kirs (40 µM BaCl2 or 40 mM CsCl) but not selective inhibitors for other K+ channels (glibenclamide, tetraethylammonium, or 4-aminopyridine). Neither removal of the endothelium nor treatment with the nitric oxide synthase inhibitor (NG-nitro-L-arginine methyl ester, 10 µM) affected the K+-induced dilation. The addition of BaCl2 to resting MCAs produced a dose-dependent constriction of 8-12%, indicating that, during resting conditions, Kirs aid in setting or determining the resting tone. The magnitude of the dilations produced by the addition of K+ or constrictions produced by BaCl2 were independent of pressure over a range of 40-100 mmHg. We conclude that Kirs, which produce a dilation when activated, exist on the vascular smooth muscle of the rat MCA. These Kirs aid in determining the resting tone of the vessel, and their function is independent of pressure over physiological pressure ranges.
in vitro; dilation; vascular smooth muscle
This article has been cited by other articles:
![]() |
C. Cao, W. Lee-Kwon, K. Payne, A. Edwards, and T. L. Pallone Descending vasa recta endothelia express inward rectifier potassium channels Am J Physiol Renal Physiol, October 1, 2007; 293(4): F1248 - F1255. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Cao, J. H. Goo, W. Lee-Kwon, and T. L. Pallone Vasa recta pericytes express a strong inward rectifier K+ conductance Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2006; 290(6): R1601 - R1607. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. J. Haddy, P. M. Vanhoutte, and M. Feletou Role of potassium in regulating blood flow and blood pressure Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2006; 290(3): R546 - R552. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. S. Park, J. Han, N. Kim, J.-H. Ko, S. J. Kim, and Y. E Earm Activation of inward rectifier K+ channels by hypoxia in rabbit coronary arterial smooth muscle cells Am J Physiol Heart Circ Physiol, December 1, 2005; 289(6): H2461 - H2467. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. You, E. M. Golding, and R. M. Bryan Jr. Arachidonic acid metabolites, hydrogen peroxide, and EDHF in cerebral arteries Am J Physiol Heart Circ Physiol, September 1, 2005; 289(3): H1077 - H1083. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. S. Clifford and Y. Hellsten Vasodilatory mechanisms in contracting skeletal muscle J Appl Physiol, July 1, 2004; 97(1): 393 - 403. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Erdos, S. A. Simandle, J. A. Snipes, A. W. Miller, and D. W. Busija Potassium Channel Dysfunction in Cerebral Arteries of Insulin-Resistant Rats Is Mediated by Reactive Oxygen Species Stroke, April 1, 2004; 35(4): 964 - 969. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Chrissobolis and C. G. Sobey Influence of Gender on K+-Induced Cerebral Vasodilatation Stroke, March 1, 2004; 35(3): 747 - 752. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Chrissobolis, J. Ziogas, C. R. Anderson, Y. Chu, F. M. Faraci, and C. G. Sobey Neuronal NO Mediates Cerebral Vasodilator Responses to K+ in Hypertensive Rats Hypertension, April 1, 2002; 39(4): 880 - 885. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Horiuchi, H. H. Dietrich, K. Hongo, T. Goto, and R. G. Dacey Jr Role of Endothelial Nitric Oxide and Smooth Muscle Potassium Channels in Cerebral Arteriolar Dilation in Response to Acidosis Stroke, March 1, 2002; 33(3): 844 - 849. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. P. Marrelli Mechanisms of endothelial P2Y1- and P2Y2-mediated vasodilatation involve differential [Ca2+]i responses Am J Physiol Heart Circ Physiol, October 1, 2001; 281(4): H1759 - H1766. [Abstract] [Full Text] [PDF] |
||||
![]() |
U. Lindauer, A. Kunz, S. Schuh-Hofer, J. Vogt, J. P. Dreier, and U. Dirnagl Nitric oxide from perivascular nerves modulates cerebral arterial pH reactivity Am J Physiol Heart Circ Physiol, September 1, 2001; 281(3): H1353 - H1363. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. M. Bryan Jr., S. P. Marrelli, M. L. Steenberg, L. A. Schildmeyer, and T. D. Johnson Effects of luminal shear stress on cerebral arteries and arterioles Am J Physiol Heart Circ Physiol, May 1, 2001; 280(5): H2011 - H2022. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Chilton and R. Loutzenhiser Functional Evidence for an Inward Rectifier Potassium Current in Rat Renal Afferent Arterioles Circ. Res., February 2, 2001; 88(2): 152 - 158. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Horiuchi, H. H. Dietrich, S. Tsugane, R. G. Dacey Jr, C. G. Sobey, and F. M. Faraci Role of Potassium Channels in Regulation of Brain Arteriolar Tone : Comparison of Cerebrum Versus Brain Stem Editorial Comment: Comparison of Cerebrum Versus Brain Stem Stroke, January 1, 2001; 32(1): 218 - 224. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Long, L. Zhang, and L. D. Longo Cerebral artery KATP- and KCa-channel activity and contractility: changes with development Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2000; 279(6): R2004 - R2014. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Chrissobolis, J. Ziogas, Y. Chu, F. M. Faraci, and C. G. Sobey Role of inwardly rectifying K+ channels in K+-induced cerebral vasodilatation in vivo Am J Physiol Heart Circ Physiol, December 1, 2000; 279(6): H2704 - H2712. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. G. Sobey and F. M. Faraci Knockout Blow for Channel Identity Crisis : Vasodilation to Potassium Is Mediated via Kir2.1 Circ. Res., July 21, 2000; 87(2): 83 - 84. [Full Text] [PDF] |
||||
![]() |
J. You, T. D. Johnson, S. P. Marrelli, J.-V. Mombouli, R. M. Bryan Jr, and F. M. Faraci P2u Receptor–Mediated Release of Endothelium-Derived Relaxing Factor/Nitric Oxide and Endothelium-Derived Hyperpolarizing Factor From Cerebrovascular Endothelium in Rats • Editorial Comment Stroke, May 1, 1999; 30(5): 1125 - 1133. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |