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

This Article Full Text Full Text (PDF) All Versions of this Article: 289/6/L902    most recent 00005.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in 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 Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Wang, L. Articles by Murphy, T. M. Search for Related Content PubMed PubMed Citation Articles by Wang, L. Articles by Murphy, T. M.

EDITORIAL FOCUS

Maturation of guinea pig tracheal strip stiffness

Department of Pediatrics and Neonatal Perinatal Research Institute, Duke University Medical Center, Durham, North Carolina

Submitted 5 January 2005 ; accepted in final form 6 June 2005

Previously, we showed the shortening velocity of guinea pig tracheal strips was the greatest in juvenile (3-wk-old) compared with infant (1-wk-old) and adult animals (3-mo-old). The greatest shortening velocity was associated with the least resistance to shortening calculated from force-velocity curves among the three age groups. It remained to be verified if the stiffness of tracheal tissue, a measure of tissue response to geometrical deformations, is different among the three age groups. We hypothesized that stiffness of intact tracheal strips is lowest in the juvenile group and that this can explain the ontogeny of airway smooth muscle resistance to shortening and shortening velocity. Static stiffness measured through stepwise deformations showed no age-related differences. Evaluation of tissue response to oscillatory deformations showed that the dynamic stiffness of unstimulated tracheal strips was 8.35 ± 0.88, 4.15 ± 1.09, and 8.21 ± 1.57 kPa, and the phase angle was 10.3 ± 2.93, 2.46 ± 0.67, and 7.87 ± 1.77° in infant, juvenile, and adult, respectively. Unstimulated juvenile strips were significantly lower in dynamic stiffness and phase angle compared with unstimulated infant or adult strips. This maturational profile was independent of muscle strip preset length or oscillation mode/amplitude but was abolished at peak of contraction to either carbachol or electric field stimulation. These results suggest that the noncontractile components of tracheal strips are less stiff and contain fewer viscous/frictional elements in juvenile than in other age groups. This may provide a functional basis for reduced resistance to length changes in juvenile airway smooth muscle.

ontogenesis; viscoelasticity

This article has been cited by other articles:

				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]

				L. E. Ford and S. H. Gilbert The importance of maturational studies in airway smooth muscle Am J Physiol Lung Cell Mol Physiol, December 1, 2005; 289(6): L898 - L901. [Full Text] [PDF]