| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Symposium Reports |
1 School of Biosciences, Museum Avenue, Cardiff University, Cardiff CF11 9BX, UK
Abstract
The majority of physiological processes proceed most favourably when O2 is in plentiful supply. However, there are a number of physiological and pathological circumstances in which this supply is reduced either acutely or chronically. A crucial homeostatic response to such arterial hypoxaemia is carotid body excitation and a resultant increase in ventilation. Central to this response in carotid body, and many other chemosensory tissues, is the rapid inhibition of ion channels by hypoxia. Since the first direct demonstration of hypoxia-evoked depression in K+ channel activity, the numbers of mechanisms which have been proposed to serve as the primary O2 sensor have been almost as numerous as the experimental strategies with which to probe their nature. Three of the current favourite candidate mechanisms are mitochondria, AMP-activated kinase and haemoxygenase-2; a fourth proposal has been NADPH oxidase, but recent evidence suggests that this enzyme plays a secondary role in the O2-sensing process. All of these proposals have attractive points, but none can fully reconcile all of the data which have accumulated over the last two decades or so, suggesting that there may, in fact, not be a unique sensing system even within a single cell type. This latter point is key, because it implies that the ability of a cell to respond appropriately to decreased O2 availability is biologically so important that several mechanisms have evolved to ensure that cellular function is never compromised during moderate to severe hypoxic insult.
(Received 26 May 2006;
accepted after revision 10 July 2006; first published online 20 July 2006)
Corresponding author P. J. Kemp: School of Biosciences, Museum Avenue, Cardiff University, Cardiff CF11 9BX, UK. Email: kemp{at}cf.ac.uk
This article has been cited by other articles:
|
|
 |
|
  K. R. Olson Hydrogen sulfide and oxygen sensing: implications in cardiorespiratory control J. Exp. Biol., September 1, 2008; 211(17): 2727 - 2734. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Trapp, M. Isabel Aller, W. Wisden, and A. V. Gourine A Role for TASK-1 (KCNK3) Channels in the Chemosensory Control of Breathing J. Neurosci., August 27, 2008; 28(35): 8844 - 8850. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. R. Olson, M. J. Healy, Z. Qin, N. Skovgaard, B. Vulesevic, D. W. Duff, N. L. Whitfield, G. Yang, R. Wang, and S. F. Perry Hydrogen sulfide as an oxygen sensor in trout gill chemoreceptors Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2008; 295(2): R669 - R680. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. L. Whitfield, E. L. Kreimier, F. C. Verdial, N. Skovgaard, and K. R. Olson Reappraisal of H2S/sulfide concentration in vertebrate blood and its potential significance in ischemic preconditioning and vascular signaling Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2008; 294(6): R1930 - R1937. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Buttigieg, S. T. Brown, M. Lowe, M. Zhang, and C. A. Nurse Functional mitochondria are required for O2 but not CO2 sensing in immortalized adrenomedullary chromaffin cells Am J Physiol Cell Physiol, April 1, 2008; 294(4): C945 - C956. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Garmier, P. Priault, G. Vidal, S. Driscoll, R. Djebbar, M. Boccara, C. Mathieu, C. H. Foyer, and R. De Paepe Light and Oxygen Are Not Required for Harpin-induced Cell Death J. Biol. Chem., December 28, 2007; 282(52): 37556 - 37566. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. T. TAYLOR and J. POUYSSEGUR Oxygen, Hypoxia, and Stress Ann. N.Y. Acad. Sci., October 1, 2007; 1113(1): 87 - 94. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Zhao, A. Adebiyi, Q. Xi, and J. H. Jaggar Hypoxia reduces KCa channel activity by inducing Ca2+ spark uncoupling in cerebral artery smooth muscle cells Am J Physiol Cell Physiol, June 1, 2007; 292(6): C2122 - C2128. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. M. Evans AMP-activated protein kinase underpins hypoxic pulmonary vasoconstriction and carotid body excitation by hypoxia in mammals Exp Physiol, September 1, 2006; 91(5): 821 - 827. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. R. Prabhakar Novel partners and mechanisms in oxygen sensing Exp Physiol, September 1, 2006; 91(5): 801 - 801. [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
