Costal and crural diaphragm function during CO2 rebreathing in awake dogs

Détails

ID Serval
serval:BIB_47562F2AD2A7
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Costal and crural diaphragm function during CO2 rebreathing in awake dogs
Périodique
Journal of Applied Physiology
Auteur(s)
Easton  P. A., Fitting  J. W., Arnoux  R., Guerraty  A., Grassino  A. E.
ISSN
8750-7587 (Print)
Statut éditorial
Publié
Date de publication
03/1993
Volume
74
Numéro
3
Pages
1406-18
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Mar
Résumé
If costal and crural diaphragm segments can perform as separate muscles, then CO2-stimulated ventilation may elicit differential segmental function. We studied diaphragm segmental length, shortening, and electromyogram (EMG) activity in 10 awake dogs chronically implanted with sonomicrometer transducers and EMG electrodes. During CO2 rebreathing, segmental shortening and EMG activity per whole tidal breath progressively increased, but segmental responses could not be differentiated at any level of CO2. With increasing CO2, resting end-expiratory length of both diaphragm segments increased. During the complete intrabreath inspiratory-expiratory cycle, costal and crural diaphragm revealed distinctive segmental function. At rest, crural shortening exceeded costal shortening in earliest inspiration, costal and especially crural shortening persisted into early expiration, and EMG activity of the crural segment was greater than that of the costal segment in earliest inspiration and showed more end-inspiratory/early expiratory [post-inspiratory inspiratory activity (PIIA)] activity. During CO2-stimulated breathing, neither segment shortened during the inspiratory flow of earliest inspiration. During CO2 rebreathing, shortening of the crural segment exceeded that of the costal segment during early inspiration and outlasted costal shortening during expiration; for both segments, shortening persisted after termination of inspiratory airflow. With increased CO2, EMG activity of the crural segment preceded that of the costal segment in earliest inspiration and was dominant into expiration, whereas costal EMG activity terminated abruptly with inspiratory flow. Thus, costal EMG PIIA was not evident during hypercapnia, whereas crural EMG PIIA was significant.(ABSTRACT TRUNCATED AT 250 WORDS)
Mots-clé
Animals Carbon Dioxide/*pharmacology Diaphragm/*physiology Dogs Electromyography/drug effects Hypercapnia/physiopathology Respiration/drug effects Respiratory Mechanics/drug effects Respiratory Muscles/drug effects/physiology
Pubmed
Web of science
Création de la notice
25/01/2008 10:43
Dernière modification de la notice
03/03/2018 16:49
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