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: 99/2/677    most recent 00165.2005v1 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 (3) Citing Articles via Google Scholar Google Scholar Articles by Xue, Z. Articles by Tepper, R. S. Search for Related Content PubMed PubMed Citation Articles by Xue, Z. Articles by Tepper, R. S.

Respiratory system responsiveness in rabbits in vivo is reduced by prolonged continuous positive airway pressure

¹HB Wells Center for Pediatric Research, Department of Pediatrics, and ³Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana; and ²Department of Medicine, University of Florida, Gainesville, Florida

Submitted 9 February 2005 ; accepted in final form 1 April 2005

Active, nonanesthetized, tracheotomized rabbits were subjected to continuous positive airway pressure (CPAP) for 4 days to determine the effects of chronic mechanical strain on lung and airway function. Rabbits were maintained for 4 days at a CPAP of 6 cmH₂O (high CPAP), at a CPAP of 0 cmH₂O (low CPAP), or without tracheostomy (no CPAP). After treatment with CPAP, changes in respiratory resistance in response to increasing concentrations of inhaled ACh were measured during mechanical ventilation to evaluate respiratory system responsiveness in vivo. Intraparenchymal bronchial segments were isolated from the lungs of all animals to evaluate airway smooth muscle responsiveness and bronchial compliance in vitro. Rabbits maintained for 4 days at high CPAP demonstrated significantly lower responsiveness to ACh compared with rabbits that were maintained at low CPAP or with no CPAP. Airways isolated from the lungs of animals subjected to the chronic application of high CPAP were also less responsive to ACh in vitro than the airways isolated from animals subjected to low CPAP or no CPAP. The persistence of the decreased responsiveness in the excised airway tissues suggests that the decreased respiratory system responsiveness observed in vivo results primarily from direct effects on the airways. The results demonstrate that the application of prolonged mechanical strain in vivo can reduce airway reactivity.

mechanical strain; airway reactivity; isolated bronchial segments; intraparenchymal airways

This article has been cited by other articles:

				N. J. Fairbank, S. C. Connolly, J. D. MacKinnon, K. Wehry, L. Deng, and G. N. Maksym Airway smooth muscle cell tone amplifies contractile function in the presence of chronic cyclic strain Am J Physiol Lung Cell Mol Physiol, September 1, 2008; 295(3): L479 - L488. [Abstract] [Full Text] [PDF]

				Z. Xue, L. Zhang, Y. Liu, S. J. Gunst, and R. S. Tepper Chronic inflation of ferret lungs with CPAP reduces airway smooth muscle contractility in vivo and in vitro J Appl Physiol, March 1, 2008; 104(3): 610 - 615. [Abstract] [Full Text] [PDF]

				Y. Bosse, A. Sobieszek, P. D. Pare, and C. Y. Seow Length Adaptation of Airway Smooth Muscle Proceedings of the ATS, January 1, 2008; 5(1): 62 - 67. [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]

				K. A. Mohammed, N. Nasreen, R. S. Tepper, and V. B. Antony Cyclic stretch induces PlGF expression in bronchial airway epithelial cells via nitric oxide release Am J Physiol Lung Cell Mol Physiol, February 1, 2007; 292(2): L559 - L566. [Abstract] [Full Text] [PDF]