J Physiol Society Membership
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Physiology in Press

First published online on March 14, 2003.
 Copyright © 2003 by The Physiological Society
This Article
Right arrow Full Text (Rapid PDF)
Right arrow All Versions of this Article:
548/3/731    most recent
2002.035998v2
2002.035998v1
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Campanucci, V. A.
Right arrow Articles by Nurse, C. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Campanucci, V. A.
Right arrow Articles by Nurse, C. A.

Received February 4, 2003
Accepted after revision February 11, 2003

A novel O2-sensing mechanism in rat glossopharyngeal neurones mediated by a halothane-inhibitable background K+ conductance

Verónica A. Campanucci1, Ian M. Fearon1, and C. A. Nurse2*

1 Department of Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1
2 Department of Biology, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1

* To whom correspondence should be addressed. E-mail: nursec{at}mcmaster.ca.

Modulation of K+ channels by hypoxia is a common O2-sensing mechanism in specialised cells. More recently, acid-sensitive TASK-like background K+ channels, which play a key role in setting the resting membrane potential, have been implicated in O2-sensing in certain cell types. Here, we report a novel O2 sensitivity mediated by a weakly pH-sensitive background K+ conductance in nitric oxide synthase (NOS)-positive neurones of the glossopharyngeal nerve (GPN). This conductance was insensitive to 30 mM TEA, 5 mM 4-aminopyridine (4-AP) and 200 µM Cd2+, but was reversibly inhibited by hypoxia (O2 tension (PO2) = 15 mmHg), 2-5 mM halothane, 10 mM barium and 1 mM quinidine. Notably, the presence of halothane occluded the inhibitory effect of hypoxia. Under current clamp, these agents depolarised GPN neurones. In contrast, arachidonic acid (5-10 µM) caused membrane hyperpolarisation and potentiation of the background K+ current. This pharmacological profile suggests the O2-sensitive conductance in GPN neurones is mediated by a class of background K+ channels different from the TASK family; it appears more closely related to the THIK (tandem pore domain halothane-inhibited K+) subfamily, or may represent a new member of the background K+ family. Since GPN neurones are thought to provide NO-mediated efferent inhibition of the carotid body (CB), these channels may contribute to the regulation of breathing during hypoxia via negative feedback control of CB function, as well as to the inhibitory effect of volatile anaesthetics (e.g. halothane) on respiration.




This article has been cited by other articles:


Home page
 J. Physiol.Home page
P. D. Smith, S. E. Brett, K. D. Luykenaar, S. L. Sandow, S. P. Marrelli, E. J. Vigmond, and D. G. Welsh
KIR channels function as electrical amplifiers in rat vascular smooth muscle
J. Physiol., February 15, 2008; 586(4): 1147 - 1160.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
R. H. Balfour and S. Trapp
Ionic currents underlying the response of rat dorsal vagal neurones to hypoglycaemia and chemical anoxia
J. Physiol., March 15, 2007; 579(3): 691 - 702.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
V. A. Campanucci, M. Zhang, C. Vollmer, and C. A. Nurse
Expression of Multiple P2X Receptors by Glossopharyngeal Neurons Projecting to Rat Carotid Body O2-Chemoreceptors: Role in Nitric Oxide-Mediated Efferent Inhibition.
J. Neurosci., September 13, 2006; 26(37): 9482 - 9493.
[Abstract] [Full Text] [PDF]

Home page
 J. Histochem. Cytochem.Home page
Y. Yamamoto and K. Taniguchi
Expression of Tandem P Domain K+ Channel, TREK-1, in the Rat Carotid Body
J. Histochem. Cytochem., April 1, 2006; 54(4): 467 - 472.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
M. G. Jonz and C. A. Nurse
Development of oxygen sensing in the gills of zebrafish
J. Exp. Biol., April 15, 2005; 208(8): 1537 - 1549.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
L. He, B. Dinger, and S. Fidone
Effect of chronic hypoxia on cholinergic chemotransmission in rat carotid body
J Appl Physiol, February 1, 2005; 98(2): 614 - 619.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
M. G Jonz, I. M Fearon, and C. A Nurse
Neuroepithelial oxygen chemoreceptors of the zebrafish gill
J. Physiol., November 1, 2004; 560(3): 737 - 752.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
R. P. Johnson, I. M. O'Kelly, and I. M. Fearon
System-specific O2 sensitivity of the tandem pore domain K+ channel TASK-1
Am J Physiol Cell Physiol, February 1, 2004; 286(2): C391 - C397.
[Abstract] [Full Text]

Home page
 Circ. Res.Home page
A.M. Gurney, O.N. Osipenko, D. MacMillan, K.M. McFarlane, R.J. Tate, and F.E.J. Kempsill
Two-Pore Domain K Channel, TASK-1, in Pulmonary Artery Smooth Muscle Cells
Circ. Res., November 14, 2003; 93(10): 957 - 964.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Copyright © 2003 The Physiological Society.