Oxygen sensitive Kv channels in the carotid body.
Hypoxic inhibition of K(+) channels has been documented in many native chemoreceptor cells, and is crucial to initiate reflexes directed to improve tissue O(2) supply. In the carotid body (CB) chemoreceptors, there is a general consensus regarding the facts that a decrease in P(O2) leads to membrane depolarization, increase of Ca(2+) entry trough voltage-dependent Ca(2+) channels and Ca(2+)-dependent release of neurotransmitters. Central to this pathway is the modulation by hypoxia of K(+) channels that triggers depolarization. However, the details of this process are still controversial, and even the molecular nature of these oxygen-sensitive K(+) (K(O2)) channels in the CB is hotly debated. Clearly there are inter-species differences, and even in the same preparation more that one K(O2) may be present. Here we recapitulate our present knowledge of the role of voltage dependent K(+) channels as K(O2) in the CB from different species, and their functional contribution to cell excitability in response to acute and chronic exposure to hypoxia.
López-López
José Ramón
JR
Departamento de Bioquímica y Biología Molecular y Fisiología, Facultad de Medicina e Instituto de Biología y Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas, Valladolid, Spain.
Pérez-García
M Teresa
MT
D000818:Animals; D002344:Carotid Body / Q000502:physiology*; D002628:Chemoreceptor Cells / Q000502:physiology*; D006801:Humans; D000860:Hypoxia / Q000378:metabolism / Q000503:physiopathology; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D010802:Phylogeny; D015221:Potassium Channels / Q000737:chemistry / Q000502:physiology*; D013045:Species Specificity
D015221:Potassium Channels