Actin Filaments Affect on Not Only Elasticity But Also Late Viscous Response in Stress Relaxation of Single Isolated Aortic Smooth Muscle Cells

The stress relaxation test was performed for cultured rat aortic smooth muscle cells (SMCs) to investigate the effect of actin filaments (AFs) on viscoelastic properties of the cells. Untreated cells and cells treated with cytochalasin D to disrupt their AFs were stretched by 70-85%, and their lengt...

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Main Authors: Kazuaki NAGAYAMA, Shinichiro YANAGIHARA, Takeo MATSUMOTO
Format: Article
Language:English
Published: The Japan Society of Mechanical Engineers 2007-06-01
Series:Journal of Biomechanical Science and Engineering
Subjects:
Online Access:https://www.jstage.jst.go.jp/article/jbse/2/3/2_3_93/_pdf/-char/en
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author Kazuaki NAGAYAMA
Shinichiro YANAGIHARA
Takeo MATSUMOTO
author_facet Kazuaki NAGAYAMA
Shinichiro YANAGIHARA
Takeo MATSUMOTO
author_sort Kazuaki NAGAYAMA
collection DOAJ
description The stress relaxation test was performed for cultured rat aortic smooth muscle cells (SMCs) to investigate the effect of actin filaments (AFs) on viscoelastic properties of the cells. Untreated cells and cells treated with cytochalasin D to disrupt their AFs were stretched by 70-85%, and their length was kept constant with a laboratory-made micro tensile tester with feed-back control to obtain their stress relaxation curve. Viscoelastic analysis with 4-parameter Maxwell model showed that the stress relaxation process of the cells could be divided into two phases with different time constants: a fast phase with a time constant in the order of minutes, and a slow phase with a time constant in the order of hours. Elastic parameters in the two phases decreased similarly by about a half with AF disruption. Viscous parameters also decreased by ∼1/3 and ∼1/4 in the fast and the slow phase, respectively, with AF disruption. No difference was observed for the relaxation time constant in the fast phase in response to AF disruption, while the time constant in the slow phase decreased significantly by about a half. Fluctuation in tension was observed in the stress relaxation curve of the untreated cells. Such fluctuation disappeared in cells treated with cytochalasin D. These results indicates that AFs have significant effects on viscosity of SMCs in the slow phase and on the fluctuation in tension, both of which may be caused by the dynamic change of AFs.
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spelling doaj.art-8688fc2e3648405ab7b1a435e9d65eb22022-12-22T03:38:58ZengThe Japan Society of Mechanical EngineersJournal of Biomechanical Science and Engineering1880-98632007-06-01239310410.1299/jbse.2.93jbseActin Filaments Affect on Not Only Elasticity But Also Late Viscous Response in Stress Relaxation of Single Isolated Aortic Smooth Muscle CellsKazuaki NAGAYAMA0Shinichiro YANAGIHARA1Takeo MATSUMOTO2Biomechanics Laboratory, Department of Mechanical Engineering, Nagoya Institute of TechnologyBiomechanics Laboratory, Department of Mechanical Engineering, Nagoya Institute of TechnologyBiomechanics Laboratory, Department of Mechanical Engineering, Nagoya Institute of TechnologyThe stress relaxation test was performed for cultured rat aortic smooth muscle cells (SMCs) to investigate the effect of actin filaments (AFs) on viscoelastic properties of the cells. Untreated cells and cells treated with cytochalasin D to disrupt their AFs were stretched by 70-85%, and their length was kept constant with a laboratory-made micro tensile tester with feed-back control to obtain their stress relaxation curve. Viscoelastic analysis with 4-parameter Maxwell model showed that the stress relaxation process of the cells could be divided into two phases with different time constants: a fast phase with a time constant in the order of minutes, and a slow phase with a time constant in the order of hours. Elastic parameters in the two phases decreased similarly by about a half with AF disruption. Viscous parameters also decreased by ∼1/3 and ∼1/4 in the fast and the slow phase, respectively, with AF disruption. No difference was observed for the relaxation time constant in the fast phase in response to AF disruption, while the time constant in the slow phase decreased significantly by about a half. Fluctuation in tension was observed in the stress relaxation curve of the untreated cells. Such fluctuation disappeared in cells treated with cytochalasin D. These results indicates that AFs have significant effects on viscosity of SMCs in the slow phase and on the fluctuation in tension, both of which may be caused by the dynamic change of AFs.https://www.jstage.jst.go.jp/article/jbse/2/3/2_3_93/_pdf/-char/encellular biomechanicsmechanical propertiesmicromanipulationnormalized tensionactin filament reorganization
spellingShingle Kazuaki NAGAYAMA
Shinichiro YANAGIHARA
Takeo MATSUMOTO
Actin Filaments Affect on Not Only Elasticity But Also Late Viscous Response in Stress Relaxation of Single Isolated Aortic Smooth Muscle Cells
Journal of Biomechanical Science and Engineering
cellular biomechanics
mechanical properties
micromanipulation
normalized tension
actin filament reorganization
title Actin Filaments Affect on Not Only Elasticity But Also Late Viscous Response in Stress Relaxation of Single Isolated Aortic Smooth Muscle Cells
title_full Actin Filaments Affect on Not Only Elasticity But Also Late Viscous Response in Stress Relaxation of Single Isolated Aortic Smooth Muscle Cells
title_fullStr Actin Filaments Affect on Not Only Elasticity But Also Late Viscous Response in Stress Relaxation of Single Isolated Aortic Smooth Muscle Cells
title_full_unstemmed Actin Filaments Affect on Not Only Elasticity But Also Late Viscous Response in Stress Relaxation of Single Isolated Aortic Smooth Muscle Cells
title_short Actin Filaments Affect on Not Only Elasticity But Also Late Viscous Response in Stress Relaxation of Single Isolated Aortic Smooth Muscle Cells
title_sort actin filaments affect on not only elasticity but also late viscous response in stress relaxation of single isolated aortic smooth muscle cells
topic cellular biomechanics
mechanical properties
micromanipulation
normalized tension
actin filament reorganization
url https://www.jstage.jst.go.jp/article/jbse/2/3/2_3_93/_pdf/-char/en
work_keys_str_mv AT kazuakinagayama actinfilamentsaffectonnotonlyelasticitybutalsolateviscousresponseinstressrelaxationofsingleisolatedaorticsmoothmusclecells
AT shinichiroyanagihara actinfilamentsaffectonnotonlyelasticitybutalsolateviscousresponseinstressrelaxationofsingleisolatedaorticsmoothmusclecells
AT takeomatsumoto actinfilamentsaffectonnotonlyelasticitybutalsolateviscousresponseinstressrelaxationofsingleisolatedaorticsmoothmusclecells