Carbon Monoxide: A Role in Carotid Body Chemoreception

Carbon monoxide (CO), produced endogenously by heme oxygenase, has been implicated as a neuronal messenger. Carotid bodies are sensory organs that regulate ventilation by responding to alterations of blood oxygen, CO2, and pH. Changes in blood gases are sensed by glomus cells in the carotid body tha...

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Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 1995-03, Vol.92 (6), p.1994-1997
Main Authors: Prabhaker, Nanduri R., Dinerman, Jay L., Agani, Faton H., Snyder, Solomon H.
Format: Article
Language:English
Subjects:
Analysis of Variance
Animals
Brain - enzymology
Brain - physiology
Carbon monoxide
Carbon Monoxide - metabolism
Carotid body
Carotid Body - physiology
Carotid sinus
Cats
Cellular immunity
Chemoreceptor Cells - drug effects
Chemoreceptor Cells - physiology
Chemoreceptors
Dendrites - physiology
Enzymes
Female
Heme Oxygenase (Decyclizing) - analysis
Heme Oxygenase (Decyclizing) - antagonists & inhibitors
Heme Oxygenase (Decyclizing) - metabolism
Hypoxia
Immunohistochemistry
Isoenzymes - analysis
Isoenzymes - antagonists & inhibitors
Isoenzymes - metabolism
Male
Membrane Potentials - drug effects
Membrane Potentials - physiology
Microsomes - enzymology
Models, Neurological
Nerves
Neurology
Neurons
Perfusion
Physiological regulation
Protoporphyrins
Protoporphyrins - pharmacology
Rats
Rats, Sprague-Dawley
Citations: Items that cite this one
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Summary:Carbon monoxide (CO), produced endogenously by heme oxygenase, has been implicated as a neuronal messenger. Carotid bodies are sensory organs that regulate ventilation by responding to alterations of blood oxygen, CO2, and pH. Changes in blood gases are sensed by glomus cells in the carotid body that synapse on afferent terminals of the carotid sinus nerve that projects to respiratory-related neurons in the brainstem. Using immunocytochemistry, we demonstrate that heme oxygenase 2 is localized to glomus cells in the cat and rat carotid bodies. Physiological studies show that zinc protoporphyrin IX, a potent heme oxygenase inhibitor, markedly increases carotid body sensory activity, while copper protoporphyrin IX, which does not inhibit the enzyme, is inactive. Exogenous CO reverses the stimulatory effects of zinc protoporphyrin IX. These results suggest that glomus cells are capable of synthesizing CO and endogenous CO appears to be a physiologic regulator of carotid body sensory activity.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.92.6.1994