title: Cellular properties and chemosensory responses of the human carotid body.
abstract: The carotid body (CB) is the major peripheral arterial chemoreceptor in mammals that mediates the acute hyperventilatory response to hypoxia. The CB grows in response to sustained hypoxia and also participates in acclimatisation to chronic hypoxaemia. Knowledge of CB physiology at the cellular level has increased considerably in recent times thanks to studies performed on lower mammals, and rodents in particular. However, the functional characteristics of human CB cells remain practically unknown. Herein, we use tissue slices or enzymatically dispersed cells to determine the characteristics of human CB cells. The adult human CB parenchyma contains clusters of chemosensitive glomus (type I) and sustentacular (type II) cells as well as nestin-positive progenitor cells. This organ also expresses high levels of the dopaminotrophic glial cell line-derived neurotrophic factor (GDNF). We found that GDNF production and the number of progenitor and glomus cells were preserved in the CBs of human subjects of advanced age. Moreover, glomus cells exhibited voltage-dependent Na(+), Ca(2+) and K(+) currents that were qualitatively similar to those reported in lower mammals. These cells responded to hypoxia with an external Ca(2+)-dependent increase of cytosolic Ca(2+) and quantal catecholamine secretion, as reported for other mammalian species. Interestingly, human glomus cells are also responsive to hypoglycaemia and together these two stimuli can potentiate each other's effects. The chemosensory responses of glomus cells are also preserved at an advanced age. These new data on the cellular and molecular physiology of the CB pave the way for future pathophysiological studies involving this organ in humans.
authors.affiliation: J. López-Barneo: Instituto de Biomedicina de Sevilla (IBiS), Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot s/n, 41013 Seville, Spain. lbarneo@us.es.
authors.forename: Patricia
authors.initials: P
authors.lastname: Ortega-Sáenz
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pardal
authors.forename: Konstantin
authors.initials: K
authors.lastname: Levitsky
authors.forename: Javier
authors.initials: J
authors.lastname: Villadiego
authors.forename: Ana Belén
authors.initials: AB
authors.lastname: Muñoz-Manchado
authors.forename: Rocío
authors.initials: R
authors.lastname: Durán
authors.forename: Victoria
authors.initials: V
authors.lastname: Bonilla-Henao
authors.forename: Ignacio
authors.initials: I
authors.lastname: Arias-Mayenco
authors.forename: Verónica
authors.initials: V
authors.lastname: Sobrino
authors.forename: Antonio
authors.initials: A
authors.lastname: Ordóñez
authors.forename: María
authors.initials: M
authors.lastname: Oliver
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Toledo-Aral
authors.forename: José
authors.initials: J
authors.lastname: López-Barneo
mesh_terms: D000200:Action Potentials; D000293:Adolescent; D000328:Adult; D053687:Adult Stem Cells / Q000166:cytology / Q000378:metabolism; D000368:Aged; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002344:Carotid Body / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D015687:Cell Hypoxia; D002478:Cells, Cultured; D002648:Child; D005260:Female; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007473:Ion Channels / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D064231:Nestin / Q000235:genetics / Q000378:metabolism; D009457:Neuroglia / Q000166:cytology / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
chemical_list: D007473:Ion Channels; D064231:Nestin; D012964:Sodium; D005947:Glucose; D011188:Potassium; D002118:Calcium