Document Detail

Maximum expiratory flow and transpulmonary pressure in the hamster.
MedLine Citation:
PMID:  730586     Owner:  NLM     Status:  MEDLINE    
Maximum expiratory flow was measured in 19 normal, anesthetized, tracheostomized, supine hamsters from records of forced deflation produced by the application of varying degrees of negative pressure to the tracheostomies of animals whose lungs had been previously inflated to a transpulmonary pressure (PL) of 25 cmH2O. Flow was measured with a pneumotachograph, volume with a constant-volume pressure plethysmograph and pleural surface pressure (Ppl) with a water-filled esophageal catheter. The esophageal pressure measurement overestimated Ppl and a simple technique was based on an estimate of the resting volume of the chest wall. This volume, at which the Ppl is zero, was calculated for anesthetized supine hamsters from the measurement of respiratory-system pressure and PL made independently of esophageal pressure and was found to be about 30% of vital capacity (VC). Flow limitation was present below 70% of VC with a tracheal deflation pressure of -30cmH2O. Negative effort dependence of flow was seen in small segments of the flow-volume curves. Mean +/- SD maximum expiratory flow at 50% VC was 52 +/- 9.5 ml/s or 9.1 VC/s. Upstream resistance was 0.09 +/- 0.03 cmH2O/ml per s.
E C Lucey; B R Celli; G L Snider
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology: respiratory, environmental and exercise physiology     Volume:  45     ISSN:  0161-7567     ISO Abbreviation:  J Appl Physiol Respir Environ Exerc Physiol     Publication Date:  1978 Dec 
Date Detail:
Created Date:  1979-03-24     Completed Date:  1979-03-24     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  7801242     Medline TA:  J Appl Physiol Respir Environ Exerc Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  840-5     Citation Subset:  IM    
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MeSH Terms
Airway Resistance
Cricetinae / physiology*
Esophagus / physiology*
Lung / physiology*
Maximal Expiratory Flow Rate
Mesocricetus / physiology*
Plethysmography, Whole Body / methods*

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

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