| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Pharmacology, The University of Melbourne, Parkville, Victoria 3010, Australia; and 2 Departments of Internal Medicine and Pharmacology, Cardiovascular Center, University of Iowa College of Medicine, Iowa City, Iowa 52242
We tested whether activation of inwardly rectifying K+ (Kir) channels, Na+-K+-ATPase, or nitric oxide synthase (NOS) play a role in K+-induced dilatation of the rat basilar artery in vivo. When cerebrospinal fluid [K+] was elevated from 3 to 5, 10, 15, 20, and 30 mM, a reproducible concentration-dependent vasodilator response was elicited (change in diameter = 9 ± 1, 27 ± 4, 35 ± 4, 43 ± 12, and 47 ± 16%, respectively). Responses to K+ were inhibited by ~50% by the Kir channel inhibitor BaCl2 (30 and 100 µM). In contrast, neither ouabain (1-100 µM, a Na+-K+-ATPase inhibitor) nor NG-nitro-L-arginine (30 µM, a NOS inhibitor) had any effect on K+-induced vasodilatation. These concentrations of K+ also hyperpolarized smooth muscle in isolated segments of basilar artery, and these hyperpolarizations were virtually abolished by 30 µM BaCl2. RT-PCR experiments confirmed the presence of mRNA for Kir2.1 in the basilar artery. Thus K+-induced dilatation of the basilar artery in vivo appears to partly involve hyperpolarization mediated by Kir channel activity and possibly another mechanism that does not involve hyperpolarization, activation of Na+-K+-ATPase, or NOS.
barium; basilar artery; nitric oxide synthase; ouabain; sodium-potassium adenosine triphosphatase
This article has been cited by other articles:
|
|
 |
|
  N. Toda, K. Ayajiki, and T. Okamura Cerebral Blood Flow Regulation by Nitric Oxide: Recent Advances Pharmacol. Rev., March 1, 2009; 61(1): 62 - 97. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Zulli, B. Ye, P. J. Wookey, B. F. Buxton, and D. L. Hare Calcitonin gene-related peptide inhibits angiotensin II-mediated vasoconstriction in human radial arteries: role of the Kir channel. J. Thorac. Cardiovasc. Surg., August 1, 2008; 136(2): 370 - 375. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 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]
|
|
|
|
 |
|
 M. R. Metea and E. A. Newman Signalling within the neurovascular unit in the mammalian retina Exp Physiol, July 1, 2007; 92(4): 635 - 640. [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]
|
|
|
|
 |
|
 R. Schubert, U. Krien, I. Wulfsen, D. Schiemann, G. Lehmann, N. Ulfig, R. W. Veh, J. R. Schwarz, and H. Gago Nitric Oxide Donor Sodium Nitroprusside Dilates Rat Small Arteries by Activation of Inward Rectifier Potassium Channels Hypertension, April 1, 2004; 43(4): 891 - 896. [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]
|
|
|
|
|
|
T. Karkanis, S. Li, J. G. Pickering, and S. M. Sims Plasticity of KIR channels in human smooth muscle cells from internal thoracic artery Am J Physiol Heart Circ Physiol, June 1, 2003; 284(6): H2325 - H2334. [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]
|
|
|
|
 |
|
 F. M. Faraci, C. G. Sobey, S. Chrissobolis, D. D. Lund, D. D. Heistad, and N. L. Weintraub Arachidonate dilates basilar artery by lipoxygenase-dependent mechanism and activation of K+ channels Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2001; 281(1): R246 - R253. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. M. Eckman and M. T. Nelson Potassium Ions as Vasodilators: Role of Inward Rectifier Potassium Channels Circ. Res., February 2, 2001; 88(2): 132 - 133. [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]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
