| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Pathology and Laboratory Medicine, James Hogg iCAPTURE Centre for Cardiovascular and Pulmonary Research, St. Paul's Hospital/Providence Health Care, University of British Columbia, Vancouver, British Columbia, Canada V6Z 1Y6
Submitted 29 August 2003 ; accepted in final form 26 January 2004
Actin polymerization as part of the normal smooth muscle response to various stimuli has been reported. The actin dynamics are believed to be necessary for cytoskeletal remodeling in smooth muscle in its adaptation to external stress and strain and for maintenance of optimal contractility. We have shown in our previous studies in airway smooth muscle that myosins polymerized in response to contractile activation as well as to adaptation at longer cell lengths. We postulated that the same response could be elicited from actins under the same conditions. In the present study, actin filament formation was quantified electron microscopically in cell cross sections. Nanometer resolution allowed us to examine regional distribution of filaments in a cell cross section. Airway smooth muscle bundles were fixed in relaxed and activated states at two lengths; muscle preparations were also fixed after a period of oscillatory strain, a condition known to cause depolymerization of myosin filaments. The results indicate that contractile activation and increased cell length nonsynergistically enhanced actin polymerization; the extent of actin polymerization was substantially less than that of myosin polymerization. Oscillatory strain increased thin filament formation. Although thin filament density was found higher in cytoplasmic areas near dense bodies, contractile activation did not preferentially enhance actin polymerization in these areas. It is concluded that actin thin filaments are dynamic structures whose length and number are regulated by the cell in response to changes in extracellular environment and that polymerization and depolymerization of thin filaments occur uniformly across the whole cell cross section.
length adaptation; oscillation; myosin filament; actin cytoskeleton; morphometrics
This article has been cited by other articles:
|
|
 |
|
  S. J. Gunst and W. Zhang Actin cytoskeletal dynamics in smooth muscle: a new paradigm for the regulation of smooth muscle contraction Am J Physiol Cell Physiol, September 1, 2008; 295(3): C576 - C587. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. D. Tang and Y. Anfinogenova Physiologic Properties and Regulation of the Actin Cytoskeleton in Vascular Smooth Muscle Journal of Cardiovascular Pharmacology and Therapeutics, June 1, 2008; 13(2): 130 - 140. [Abstract] [PDF]
|
|
|
|
 |
|
 W. Zhang and S. J. Gunst Interactions of Airway Smooth Muscle Cells with Their Tissue Matrix: Implications for Contraction Proceedings of the ATS, January 1, 2008; 5(1): 32 - 39. [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]
|
|
|
|
|
|
R. W. Mitchell, M. L. Dowell, J. Solway, and O. J. Lakser Force Fluctuation induced Relengthening of Acetylcholine-contracted Airway Smooth Muscle Proceedings of the ATS, January 1, 2008; 5(1): 68 - 72. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Anfinogenova, R. Wang, Q.-f. Li, A. M. Spinelli, and D. D. Tang Abl Silencing Inhibits CAS-Mediated Process and Constriction in Resistance Arteries Circ. Res., August 17, 2007; 101(4): 420 - 428. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Ali, L. Chin, P. D. Pare, and C. Y. Seow Mechanism of partial adaptation in airway smooth muscle after a step change in length J Appl Physiol, August 1, 2007; 103(2): 569 - 577. [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]
|
|
|
|
|
|
A. V. Smolensky and L. E. Ford The extensive length-force relationship of porcine airway smooth muscle J Appl Physiol, May 1, 2007; 102(5): 1906 - 1911. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. Zhang and S. J. Gunst Dynamic association between {alpha}-actinin and {beta}-integrin regulates contraction of canine tracheal smooth muscle J. Physiol., May 1, 2006; 572(3): 659 - 676. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. S. P. Silveira, J. P. Butler, and J. J. Fredberg Length adaptation of airway smooth muscle: a stochastic model of cytoskeletal dynamics J Appl Physiol, December 1, 2005; 99(6): 2087 - 2098. [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]
|
|
|
|
|
|
C. Y. Seow Myosin filament assembly in an ever-changing myofilament lattice of smooth muscle Am J Physiol Cell Physiol, December 1, 2005; 289(6): C1363 - C1368. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. A. Smith, B. Tolloczko, J. G. Martin, and P. Grutter Probing the Viscoelastic Behavior of Cultured Airway Smooth Muscle Cells with Atomic Force Microscopy: Stiffening Induced by Contractile Agonist Biophys. J., April 1, 2005; 88(4): 2994 - 3007. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. V Smolensky, J. Ragozzino, S. H Gilbert, C. Y Seow, and L. E Ford Length-dependent filament formation assessed from birefringence increases during activation of porcine tracheal muscle J. Physiol., March 1, 2005; 563(2): 517 - 527. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. T. Sylvester The tone of pulmonary smooth muscle: ROK and Rho music? Am J Physiol Lung Cell Mol Physiol, October 1, 2004; 287(4): L624 - L630. [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
