Document Detail

Localized compliance of small airways in excised rat lungs using microfocal X-ray computed tomography.
MedLine Citation:
PMID:  14766787     Owner:  NLM     Status:  MEDLINE    
Airway compliance is a key factor in understanding lung mechanics and is used as a clinical diagnostic index. Understanding such mechanics in small airways physiologically and clinically is critical. We have determined the "morphometric change" and "localized compliance" of small airways under "near"-physiological conditions; namely, the airways were embedded in parenchyma without dehydration and fixation. Previously, we developed a two-step method to visualize small airways in detail by staining the lung tissue with a radiopaque solution and then visualizing the tissue with a cone-beam microfocal X-ray computed tomography system (Sera et al. J Biomech 36: 1587-1594, 2003). In this study, we used this technique to analyze changes in diameter and length of the same small airways ( approximately 150 microm ID) and then evaluated the localized compliance as a function of airway generation (Z). For smaller (<300-microm-diameter) airways, diameter was 36% larger at end-tidal inspiration and 89% larger at total lung capacity; length was 18% larger at end-tidal inspiration and 43% larger at total lung capacity than at functional residual capacity. Diameter, especially at smaller airways, did not behave linearly with V(1/3) (where V is volume). With increasing lung pressure, diameter changed dramatically at a particular pressure and length changed approximately linearly during inflation and deflation. Percentage of airway volume for smaller airways did not behave linearly with that of lung volume. Smaller airways were generally more compliant than larger airways with increasing Z and exhibited hysteresis in their diameter behavior. Airways at higher Z deformed at a lower pressure than those at lower Z. These results indicated that smaller airways did not behave homogeneously.
Toshihiro Sera; Hideki Fujioka; Hideo Yokota; Akitake Makinouchi; Ryutaro Himeno; Robert C Schroter; Kazuo Tanishita
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Publication Detail:
Type:  In Vitro; Journal Article     Date:  2004-02-06
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  96     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2004 May 
Date Detail:
Created Date:  2004-04-12     Completed Date:  2004-12-14     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1665-73     Citation Subset:  IM    
Center for Life Science and Technology, School of Fundamental Science and Technology, Keio University, Yokohama 223-8522, Japan.
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MeSH Terms
Bronchi / anatomy & histology,  physiology*
Equipment Design
Functional Residual Capacity
Imaging, Three-Dimensional
Lung Compliance*
Models, Anatomic
Models, Biological
Radiography, Thoracic*
Rats, Wistar
Time Factors
Tomography, X-Ray Computed* / instrumentation
Total Lung Capacity

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

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