%0 Journal Article
%A Ortega-Sáenz, Patricia
%A Pascual, Alberto
%A Gómez-Díaz, Raquel
%A López-Barneo, José
%T Acute oxygen sensing in heme oxygenase-2 null mice.
%D 2006
%@ 0022-1295
%U http://hdl.handle.net/10668/1703
%X Hemeoxygenase-2 (HO-2) is an antioxidant enzyme that can modulate recombinant maxi-K(+) channels and has been proposed to be the acute O(2) sensor in the carotid body (CB). We have tested the physiological contribution of this enzyme to O(2) sensing using HO-2 null mice. HO-2 deficiency leads to a CB phenotype characterized by organ growth and alteration in the expression of stress-dependent genes, including the maxi-K(+) channel alpha-subunit. However, sensitivity to hypoxia of CB is remarkably similar in HO-2 null animals and their control littermates. Moreover, the response to hypoxia in mouse and rat CB cells was maintained after blockade of maxi-K(+) channels with iberiotoxin. Hypoxia responsiveness of the adrenal medulla (AM) (another acutely responding O(2)-sensitive organ) was also unaltered by HO-2 deficiency. Our data suggest that redox disregulation resulting from HO-2 deficiency affects maxi-K(+) channel gene expression but it does not alter the intrinsic O(2) sensitivity of CB or AM cells. Therefore, HO-2 is not a universally used acute O(2) sensor.
%K Animales
%K Animales Recién Nacidos
%K Calcio
%K Cuerpo Carotídeo
%K Catecolaminas
%K Células Cromafines
%K Ciclofilinas
%K Expresión Génica
%K Hemo Oxigenasa (Deciclizadora)
%K Hemo-Oxigenasa 1
%K Subunidades alfa de los Canales de Potasio de Gran Conductancia Activados por Calcio
%K Canales de Potasio de Gran Conductancia Activados por el Calcio
%K Ratones
%K Ratones Consanguíneos C57BL
%K Ratones Noqueados
%K Tamaño de los Órganos
%K Oxígeno
%K Presión Parcial
%K Técnicas de Placa-Clamp
%K Péptidos
%K Bloqueadores de los Canales de Potasio
%K Ratas
%K Médula Suprarrenal
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