Document Detail

Influence of vagal afferents on diphasic ventilatory response to hypoxia in newborn lambs.
MedLine Citation:
PMID:  7740209     Owner:  NLM     Status:  MEDLINE    
The effect of vagal afferents on the ventilatory response to hypoxia was studied in eleven awake newborn lambs. Tests were repeated before and after vagotomy in the same lambs in two conditions: with intact upper airways and after intubation. During hypoxia, a diphasic pattern of ventilatory response was observed in both vagotomized and intact lambs. However, face mask-breathing vagotomized lambs had a blunted increase in ventilation (VI) to hypoxia as compared with intact lambs (P = 0.0001) and they showed an expiratory braking during all hypoxic time. Furthermore, the normal increase in frequency (f) to hypoxia was abolished after vagotomy. After intubation, expiratory braking disappeared and, consequently, magnitude of the VI response to hypoxia was similar in intact and vagotomized lambs. These changes were due to improved tidal volume response in vagotomized intubated lambs (P < 0.002) with no significant change in f response. We concluded that, in awake newborn lambs, vagal afferents are essential for maintaining the pattern and the magnitude of the ventilatory response to hypoxia, the latter by controlling the motor output to the larynx.
C Delacourt; E Canet; J P Praud; M A Bureau
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Respiration physiology     Volume:  99     ISSN:  0034-5687     ISO Abbreviation:  Respir Physiol     Publication Date:  1995 Jan 
Date Detail:
Created Date:  1995-06-07     Completed Date:  1995-06-07     Revised Date:  2009-11-11    
Medline Journal Info:
Nlm Unique ID:  0047142     Medline TA:  Respir Physiol     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  29-39     Citation Subset:  IM    
Jeremy Rill Center, Département de Pédiatrie, Université de Sherbrooke, Québec, Canada.
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MeSH Terms
Animals, Newborn / physiology*
Anoxia / physiopathology*
Blood Gas Analysis
Infant, Newborn
Lung / innervation*
Pulmonary Ventilation / physiology*
Sheep / physiology*
Vagus Nerve / physiology*

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