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High Altitude Physiology andPathophysiology : fromOrganism to Molecule
Part I : Oxygen sensing
Jean-Marc PequignotUMR 5123: PHYSIOLOGIE intégrative, cellulaire et moléculaire CNRS,
Université Claude Bernard Lyon I, France
Hypoxic Hypoxic chemoreflexchemoreflex
Low arterial PO2
Carotid Bodies sense Low PO2
Sympatheticnervous system
Other central pathways
Central integration in brainstem sites
Respiratory motoneurons
Increased ventilation
HematopoieticPathway (Hb)
Cellular elements of the carotidbody
The anatomical localization of thecarotid body
Ultrastructure of the glomus cells
The firing rate in response to gradual increase of hypoxia level
Measurement of hypoxic ventilatoryresponse
Chemoreception / chemotransduction
Peripheral chemosensitivity : a model for O2 sensing
O2 sensing and chemotransductionin the carotid body
Catecholamine responses to hypoxia in the carotid body
Hypoxia
Functional reorganization
Cell dysfunctions
Pathophysiology
Cellular phenotypicremodeling
Acclimatization
Cell Plasticity
Catecholaminergic response to hypoxia in the carotid body
Model of ventilatory acclimatizationto hypoxia
Mount Everest in utero (Sir John Barcroft, in 1930s)
Fetus vs. Adult chemosensitivity
Role of dopamine in carotid body resetting
Neonatal maturation of thechemosensitivity