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In vitro Measurements of Tracheal Constriction Using Mice
Published on: June 25, 2012
Phasic activity in the airways smooth muscle
1Laboratorio de Neurofisiología, Facultad de Medicina, Universidad Autónoma de Querétaro, México.
Acta Physiologica, Pharmacologica Et Therapeutica Latinoamericana : Organo De La Asociacion Latinoamericana De Ciencias Fisiologicas Y [De] La Asociacion Latinoamericana De Farmacologia
|January 1, 1991
Summary
Respiratory oscillations in cats and rats are linked to vagal stimulation and sympathetic control of airway smooth muscle. Mechanical factors like pressure and lung distension also play a role.
Area of Science:
- Physiology
- Respiratory System Mechanics
Background:
- Oscillations in breathing pressure/flow records are common in anesthetized animals.
- These oscillations have been observed to share properties with vagal stimulation responses.
Purpose of the Study:
- To further investigate the nature of respiratory oscillations.
- To differentiate these oscillations from known tone changes.
- To explore the role of mechanical factors and sympathetic control.
Main Methods:
- Observations in anesthetized cats and rats.
- Examining interference patterns with vagal stimulation.
- Applying pressure pulses to the tracheal cannula.
- Studying responses to sudden lung distension.
Main Results:
- Oscillations confirmed to interfere with vagal stimulation responses.
- Oscillations confirmed as distinct from tone changes.
- Oscillations shown to depend on sympathetic control of airway smooth muscle.
- Mechanical factors (pressure, volume, airflow rate) identified as important stimuli.
- Initial bronchial wall tension found to be significant.
Conclusions:
- Mechanical stimulation of airways is effective under facilitatory sympathetic influence.
- Sympathetic system plays a key role in modulating airway smooth muscle activity.
- Respiratory oscillations are a complex phenomenon involving both mechanical and neural factors.
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