Document Detail

Ventilatory and upper-airway resistance responses to upper-airway cooling and CO2 in anaesthetised rats.
MedLine Citation:
PMID:  7892113     Owner:  NLM     Status:  MEDLINE    
The effects of upper airway (UA) cool air and CO2 on breathing and on laryngeal and supraglottic resistances were studied in anaesthetised rats breathing spontaneously through a tracheostomy. Warm, humidified air containing 0, 5 and 9-10% CO2 and cool, room-humidity air were delivered at constant flow to either the isolated larynx to exit through a pharyngotomy or to the supraglottic UA to exit through the mouth and/or nose (nose open or sealed). Spontaneous tracheal airflow and UA airflows, temperatures and pressures were recorded. CO2 had no effect on breathing but caused a slight increase in laryngeal resistance which was abolished by cutting the superior laryngeal nerves (SLN). Cool air caused a decrease in respiratory frequency and/or peak inspiratory flow when applied to the isolated larynx or to the supraglottic airway with the nose closed. These effects were abolished by SLN section. With the nose open, the ventilatory inhibition was not abolished by SLN section. Cool air also caused substantial decreases in laryngeal and supraglottic resistances which were attenuated by SLN section and which persisted following recurrent laryngeal nerve section. In conclusion, whilst UA cooling inhibits breathing and decreases UA resistances, UA CO2 has minimal effects.
K D O'Halloran; A K Curran; A Bradford
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Pflügers Archiv : European journal of physiology     Volume:  429     ISSN:  0031-6768     ISO Abbreviation:  Pflugers Arch.     Publication Date:  1994 Dec 
Date Detail:
Created Date:  1995-04-20     Completed Date:  1995-04-20     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0154720     Medline TA:  Pflugers Arch     Country:  GERMANY    
Other Details:
Languages:  eng     Pagination:  262-6     Citation Subset:  IM    
Department of Physiology, Royal College of Surgeons in Ireland, Dublin 2.
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MeSH Terms
Airway Resistance*
Carbon Dioxide / metabolism*
Cold Temperature*
Larynx / physiology*
Rats, Wistar
Respiratory Function Tests
Trachea / physiology
Reg. No./Substance:
124-38-9/Carbon Dioxide

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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