Acute oxygen sensing: diverse but convergent mechanisms in airway and arterial chemoreceptors

Airway neuroepithelial bodies sense changes in inspired O-2, whereas arterial O-2 levels are monitored primarily by the carotid body. Both respond to hypoxia by initiating corrective cardiorespiratory reflexes, thereby optimising gas exchange in the face of a potentially deleterious O-2 supply. One unifying theme underpinning chemotransduction in these tissues is K+ channel inhibition. However, the transduction components, from O-2 sensor to K+ channel, display considerable tissue specificity yet result in analogous end points. Here we highlight how emerging data are contributing to a more complete understanding of O-2 chemosensing at the molecular level.