Document Detail

New perspectives on the mechanical basis for airway hyperreactivity and airway hypersensitivity in asthma.
MedLine Citation:
PMID:  16902064     Owner:  NLM     Status:  MEDLINE    
We revisit the airway wall model of Lambert et. al. (Lambert RK, Wiggs BR, Kuwano K, Hogg JC, and Pare PD. J Appl Physiol 74: 2771-2781, 1993). We examine in detail the notion of a general airway bistability such that the airway lumen can suddenly decrease from a relatively open to a relatively closed condition without needing additional increase in active airway smooth muscle (ASM) tension during the stimulation. The onset of this bistability is an emergent consequence of the balance of forces associated with airway wall properties, parenchymal tissue properties, maximum lung elastic recoil, and the maximum stress that the ASM can generate. In healthy lungs, we find that all these properties reside in conditions that largely prevent the emergence of the bistability even during maximum ASM stimulation. In asthmatic airways, however, the airway wall and ASM remodeling conditions can tip the balance so as to promote the onset of the bistability at a lower dose of ASM stimulation (enhanced sensitivity) and then work to amplify the maximum constriction reached by each airway (enhanced reactivity). Hence, a larger fraction of asthmatic airways can display overall airway hyperreactivity. Simulations studies examine the role of increasing ASM maximum tension, airway wall stiffening, reduced lung volume, and decreased parenchymal tethering. Results predict that the single most important factor causing this airway hyperreactivity is amplified maximum ASM tension and not a thickening of the airway wall per se.
Derek A Affonce; Kenneth R Lutchen
Related Documents :
17494784 - Safety of sputum induction with hypertonic saline solution in exercise-induced bronchoc...
9485974 - Oxygen enrichment during emergence with the laryngeal mask--the 't-bag' versus the t-pi...
2951794 - The combination of fenoterol and ipratropium bromide in bronchial asthma: comparison of...
3813194 - Hypotonic and isotonic aerosols increase bronchial reactivity in basenji-greyhound dogs.
16521844 - Effect of carbohydrate intake on half-marathon performance of well-trained runners.
15593364 - Six-month and one-year followup of 23 weeks of aerobic exercise for individuals with fi...
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2006-08-10
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  101     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2006 Dec 
Date Detail:
Created Date:  2006-11-19     Completed Date:  2007-01-04     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:  1710-9     Citation Subset:  IM    
Biomedical Engineering Department, Boston University, 44 Cummington St., Boston, MA 02215, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Asthma / physiopathology*
Bronchial Hyperreactivity / physiopathology*
Computer Simulation
Lung / physiopathology*
Mechanotransduction, Cellular*
Models, Biological*
Muscle, Smooth / physiopathology*
Shear Strength
Stress, Mechanical
Grant Support
Erratum In:
J Appl Physiol. 2007 Mar;102(3):1296

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

Previous Document:  Effect of a short-term diet and exercise intervention on inflammatory/anti-inflammatory properties o...
Next Document:  Effects of progressive and maximal exercise on plasma levels of adhesion molecules in athletes with ...