Ventilatory response in the fetal lamb following peripheral chemodenervation.
J Appl Physiol Respir Environ Exerc Physiol
; 42(4): 630-5, 1977 Apr.
Article
in En
| MEDLINE
| ID: mdl-16861
ABSTRACT
Carotid infusions of sodium cyanide solution and perfusions of hypoxemic or hypercapnic fetal blood were done before and after peripheral chemoreceptor denervation. Step changes in PaO2 ranged from -11 to -22 Torr; step changes in PaCO2 ranged from +17 to +42 Torr. The cyanide dose was 0.2 mg/kg per loop system. Control perfusions consisted of 25 ml of fetal blood without changes in pH and blood gases. A ventilatory response occurred in the majority of all experimental perfusions regardless of innervation status of the peripheral chemoreceptors. No response occurred with control perfusions. There was a marked variability in the time of onset of ventilatory activity with a delay of greater than 10 s occurring following most perfusions. These studies demonstrate that the fetus has an attenuated ventilatory response to chemical stimuli and that hypoxia stimulates ventilation in the absence of peripheral chemoreceptors.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Respiration
/
Carotid Body
/
Lung
Limits:
Animals
Language:
En
Journal:
J Appl Physiol Respir Environ Exerc Physiol
Year:
1977
Document type:
Article