Interrelationships among airway CO2, airway pressure, and breathing frequency. J Appl Physiol Respir Environ Exerc Physiol 1982 Jan;52(1):190-7
Date
01/01/1982Pubmed ID
6800986DOI
10.1152/jappl.1982.52.1.190Scopus ID
2-s2.0-0019989359 (requires institutional sign-in at Scopus site) 2 CitationsAbstract
The breathing frequency response to changes in airway CO2 of a vascularly isolated lobe of the canine lung has previously been shown to be primarily dependent on CO2-mediated changes in airway pressure. This study was carried out to determine what contribution changes in airway pressure make in the whole lung airway CO2-mediated breathing frequency response. Mongrel dogs were anesthetized and placed on cardiopulmonary bypass. Diaphragm electromyogram (EMG) was used to monitor respiratory center output and to trigger ventilation of the lungs. Isoproterenol administered to the lungs prevented hypocapnic airway constriction but only partially blocked the decrease in breathing frequency, suggesting that in the whole lung preparation, airway CO2 in part alters breathing frequency through a direct effect on pulmonary receptors. At constant positive end-expired pressures (1-6 Torr), 0% airway CO2 produced greater increases in expiratory time than 10% CO2. Thus airway CO2 can affect breathing frequency in the absence of CO2-related changes in airway pressure at pressures that would produce lung volumes similar to those observed at end expiration in the intact animal. An argument is presented that the receptors directly affected by CO2 are probably not located in the airways constricted by hypocapnia.
Author List
Nilsestuen JO, Coon RL, Zuperku EJ, Kampine JPAuthor
Edward J. Zuperku PhD, MS Emeritus Professor in the Anesthesiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsCarbon Dioxide
Dogs
Isoproterenol
Lung
Positive-Pressure Respiration
Pressure
Respiration
Respiration, Artificial
Respiratory Physiological Phenomena
