| Closing and opening pressures in the intrapulmonary airways of rats. | |
| | |
MedLine Citation:
|
PMID: 622514 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Pressures at which the peripheral airways (PA) and terminal bronchioles (TB), open and closed, were studied in rats' lungs in vitro. Airway luminal diameter was directly measured at diminishing transbronchial pressure (closing) and increasing transbronchial pressure (opening) by means of a stereomicroscope with a calibrated eyepiece. The PA and TB had internal diameters at 100 mm H2O ranging from 173 to 306 micrometer and 122 to 204 micrometer, respectively. Most of the airways closed suddenly in the pressure range between 75 and 5 mm H2O and only a few were still open at zero pressure. Closure began in the distal portion of the PA and mid-portion of the TB usually in a concentric manner. Terminal bronchioles and PA that initially were prepared at room temperature instead of at 0 degrees C often contained air at zero pressure and showed a decreased response to acetylcholine. Subthreshold concentrations of acetylcholine increased the critical closing pressure by more than 100%. The critical opening pressure was considerably higher than the corresponding closing pressure. It is proposed that bronchiolar closure depends on the tone of the airway smooth muscle, the elasticity of the airway wall and probably on the surface tension of the liquid lining the mucosal membrane. |
| | |
Authors:
|
G N Melville; J Iravani; H G Richter |
Related Documents
:
|
11132744 - Flumazenil abolishes midazolam-induced increase in the work of nasal breathing. 3086824 - Effect of endotracheal continuous positive airway pressure on sensitivity to carbon dio... 16650974 - Effect of cpap on brachial-ankle pulse wave velocity in patients with osahs: an open-la... 1099524 - Hyaline membrane disease treated with early nasal end-expiratory pressure: one year's e... 9834264 - Involvement of nitric oxide in human transient lower esophageal sphincter relaxations a... 605914 - Diaphragm function and lung involvement in systemic lupus erythematosus. |
Publication Detail:
|
Type: In Vitro; Journal Article |
Journal Detail:
|
Title: Respiration; international review of thoracic diseases Volume: 35 ISSN: 0025-7931 ISO Abbreviation: Respiration Publication Date: 1978 |
Date Detail:
|
Created Date: 1978-03-10 Completed Date: 1978-03-10 Revised Date: 2009-11-11 |
Medline Journal Info:
|
Nlm Unique ID: 0137356 Medline TA: Respiration Country: SWITZERLAND |
Other Details:
|
Languages: eng Pagination: 22-9 Citation Subset: IM |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Acetylcholine
/
pharmacology Animals Bronchi / anatomy & histology, physiology* Female Pressure Rats Temperature |
| Chemical | |
Reg. No./Substance:
|
51-84-3/Acetylcholine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Influence of pulmonary hypertension on pulmonary diffusing capacity in patients with mitral stenosis...
Next Document: Physiological assessment of severe chronic asthma in children.