HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 96/3/1161    most recent 01082.2003v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (8) Citing Articles via Google Scholar Google Scholar Articles by Noble, P. B. Articles by Mitchell, H. W. Search for Related Content PubMed PubMed Citation Articles by Noble, P. B. Articles by Mitchell, H. W.

Intraluminal pressure oscillation enhances subsequent airway contraction in isolated bronchial segments

Physiology, School of Biomedical and Chemical Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia

Submitted 6 October 2003 ; accepted in final form 14 November 2003

A period of deep inspiration in humans has been shown to attenuate subsequent bronchoconstriction, a phenomenon termed bronchoprotection. The bronchoprotective effect of deep inspiration may be caused though a depression in the force production of airway smooth muscle (ASM). We determined the response of whole airway segments and isolated ASM to a period of cyclic stretches. Isovolumetric contraction to electrical field stimulation (EFS) was assessed in porcine bronchial segments before and after intraluminal pressure oscillation from 5 to 25 cmH₂O for 10 min at 0.5 Hz. Morphometry showed that this pressure oscillation stretched ASM length by 21%. After pressure oscillation, the response to EFS was not reduced but instead was modestly enhanced (P < 0.01). Airway responses to EFS returned to preoscillation levels 10 min after the end of oscillation. The increase in EFS response after pressure oscillation was not altered by the addition of indomethacin. In a separate experiment, we assessed isometric force in isolated ASM strips before and after length oscillation. The amplitude, frequency, and duration of length oscillation were similar to those induced in bronchial segments. In contrast to bronchial segments, length oscillation of ASM produced a significant depression in isometric force induced by EFS (P < 0.01). These results suggest that the response of ASM to length oscillation is modified by the airway wall. They also suggest that the phenomenon of bronchoprotection reported in some in vivo studies may not be an intrinsic property of the airway.

airway smooth muscle; bronchoconstriction; bronchoprotection; bronchus; deep inspiration

This article has been cited by other articles:

				J. H. T. Bates, A. Cojocaru, and L. K. A. Lundblad Bronchodilatory effect of deep inspiration on the dynamics of bronchoconstriction in mice J Appl Physiol, November 1, 2007; 103(5): 1696 - 1705. [Abstract] [Full Text] [PDF]

				P. B. Noble, P. K. McFawn, and H. W. Mitchell Responsiveness of the isolated airway during simulated deep inspirations: effect of airway smooth muscle stiffness and strain J Appl Physiol, September 1, 2007; 103(3): 787 - 795. [Abstract] [Full Text] [PDF]

				S. S. An, T. R. Bai, J. H. T. Bates, J. L. Black, R. H. Brown, V. Brusasco, P. Chitano, L. Deng, M. Dowell, D. H. Eidelman, et al. Airway smooth muscle dynamics: a common pathway of airway obstruction in asthma Eur. Respir. J., May 1, 2007; 29(5): 834 - 860. [Abstract] [Full Text] [PDF]

				P. B. Noble, A. Sharma, P. K. McFawn, and H. W. Mitchell Elastic properties of the bronchial mucosa: epithelial unfolding and stretch in response to airway inflation J Appl Physiol, December 1, 2005; 99(6): 2061 - 2066. [Abstract] [Full Text] [PDF]

				P. B. Noble, A. Sharma, P. K. McFawn, and H. W. Mitchell Airway narrowing in porcine bronchi with and without lung parenchyma Eur. Respir. J., November 1, 2005; 26(5): 804 - 811. [Abstract] [Full Text] [PDF]

				S. R. Khangure, P. B. Noble, A. Sharma, P. Y. Chia, P. K. McFawn, and H. W. Mitchell Cyclical elongation regulates contractile responses of isolated airways J Appl Physiol, September 1, 2004; 97(3): 913 - 919. [Abstract] [Full Text] [PDF]