PCO2 affects tracheal tone during apnea in anesthetized dogs.
J Appl Physiol (1985)
; 81(3): 1184-9, 1996 Sep.
Article
em En
| MEDLINE
| ID: mdl-8889752
ABSTRACT
We hypothesized that CO2, like hypoxia and withdrawal of pulmonary slowly adapting receptor input, would cause tracheal constriction during neural apnea (absence of phrenic activity). In seven anesthetized paralyzed dogs ventilated to neural apnea, we increased arterial PCO2 (PaCO2) in steps by adding CO2 to the inspirate while keeping ventilation constant. Increases in PaCO2 caused tracheal constriction during neural apnea in all dogs; 69 +/- 26 (SD)% of the change in tracheal diameter occurred during neural apnea. Average sensitivity of tracheal diameter to CO2 was 0.44 mm/Torr PaCO2. Our data suggest that central chemoreceptor inputs to brain stem neurons controlling smooth muscle of the extrathoracic airway bypass central mechanisms generating inspiration.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Apneia
/
Traqueia
/
Troca Gasosa Pulmonar
/
Ventilação Pulmonar
Limite:
Animals
Idioma:
En
Revista:
J Appl Physiol (1985)
Assunto da revista:
FISIOLOGIA
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Canadá