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: 290/6/L1227    most recent 00299.2005v1 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 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 (5) Citing Articles via Google Scholar Google Scholar Articles by Ito, S. Articles by Suki, B. Search for Related Content PubMed PubMed Citation Articles by Ito, S. Articles by Suki, B.

Viscoelastic and dynamic nonlinear properties of airway smooth muscle tissue: roles of mechanical force and the cytoskeleton

Satoru Ito,^1,2 Arnab Majumdar,¹ Hiroaki Kume,² Kaoru Shimokata,² Keiji Naruse,³ Kenneth R. Lutchen,¹ Dimitrije Stamenovi,¹ and Béla Suki¹

¹Department of Biomedical Engineering, Boston University, Boston, Massachusetts; and Departments of ²Respiratory Medicine and ³Physiology, Nagoya University Graduate School of Medicine, Nagoya, Japan

Submitted 11 July 2005 ; accepted in final form 12 January 2006

The viscoelastic and dynamic nonlinear properties of guinea pig tracheal smooth muscle tissues were investigated by measuring the storage (G') and loss (G") moduli using pseudorandom small-amplitude length oscillations between 0.12 and 3.5 Hz superimposed on static strains of either 10 or 20% of initial length. The G" and G' spectra were interpreted using a linear viscoelastic model incorporating damping (G) and stiffness (H), respectively. Both G and H were elevated following an increase in strain from 10 to 20%. There was no change in harmonic distortion (K_d), an index of dynamic nonlinearity, between 10 and 20% strains. Application of methacholine at 10% strain significantly increased G and H while it decreased K_d. Cytochalasin D, isoproterenol, and HA-1077, a Rho-kinase inhibitor, significantly decreased both G and H but increased K_d. Following cytochalasin D, G, H, and K_d were all elevated when mean strain increased from 10 to 20%. There were no changes in hysteresivity, G/H, under any condition. We conclude that not all aspects of the viscoelastic properties of tracheal smooth muscle strips are similar to those previously observed in cultured cells. We attribute these differences to the contribution of the extracellular matrix. Additionally, using a network model, we show that the dynamic nonlinear behavior, which has not been observed in cell culture, is associated with the state of the contractile stress and may derive from active polymerization within the cytoskeleton.

asthma; computational model; mechanical stress; mechanics; stiffness

This article has been cited by other articles:

				S. Ito, H. Kume, K. Naruse, M. Kondo, N. Takeda, S. Iwata, Y. Hasegawa, and M. Sokabe A Novel Ca2+ Influx Pathway Activated by Mechanical Stretch in Human Airway Smooth Muscle Cells Am. J. Respir. Cell Mol. Biol., April 1, 2008; 38(4): 407 - 413. [Abstract] [Full Text] [PDF]

				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]