Multifocal animated imaging of changes in cellular oxygen and calcium concentrations and membrane potential within the intact adult mouse carotid body ex vivo.
Am J Physiol Cell Physiol
; 301(2): C266-71, 2011 Aug.
Article
en En
| MEDLINE
| ID: mdl-21525432
ABSTRACT
Carotid body (CB) type I cell hypoxia-sensing function is assumed to be based on potassium channel inhibition. Subsequent membrane depolarization initiates an intracellular calcium increase followed by transmitter release for excitation of synapses with linked nerve endings. Several reports, however, contradict this generally accepted concept by showing that type I cell oxygen-sensing properties vary significantly depending on the method of their isolation. We report therefore for the first time noninvasive mapping of the oxygen-sensing properties of type I cells within the intact adult mouse CB ex vivo by using multifocal Nipkow disk-based imaging of oxygen-, calcium- and potential-sensitive cellular dyes. Characteristic type I cell clusters were identified in the compact tissue by immunohistochemistry because of their large cell nuclei combined with positive tyrosine hydroxylase staining. The cellular calcium concentrations in these cell clusters either increased or decreased in response to reduced tissue oxygen concentrations. Under control conditions, cellular potential oscillations were uniform at â¼0.02 Hz. Under hypoxia-induced membrane depolarization, these oscillations ceased. Simultaneous increases and decreases in potential of these cell clusters resulted from spontaneous burstlike activities lasting â¼1.5 s. type I cells, identified during the experiments by cluster formation in combination with large cell nuclei, seem to respond to hypoxia with heterogeneous kinetics.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Oxígeno
/
Cuerpo Carotídeo
/
Calcio
/
Señalización del Calcio
/
Imagen de Colorante Sensible al Voltaje
/
Microscopía Fluorescente
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Am J Physiol Cell Physiol
Asunto de la revista:
FISIOLOGIA
Año:
2011
Tipo del documento:
Article
País de afiliación:
Alemania