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Measuring the Stiffness of Ex Vivo Mouse Aortas Using Atomic Force Microscopy
Published on: October 19, 2016
Smooth muscle stiffness variation due to external longitudinal oscillations
Y Du1, A M Al-Jumaily, H Shukla
1Biomedical Engineering Centre (BioMEC), Auckland University of Technology, Auckland, New Zealand.
Journal of Biomechanics
|June 15, 2007
Summary
External oscillations decrease airway smooth muscle (ASM) stiffness. Increasing oscillation frequency and amplitude reduce dynamic and static stiffness, potentially by increasing actin-myosin detachments.
Area of Science:
- Biomedical Engineering
- Respiratory Physiology
- Muscle Mechanics
Background:
- Airway smooth muscle (ASM) contraction is central to respiratory function and diseases like asthma.
- Understanding ASM mechanical properties under dynamic conditions is crucial for developing effective therapies.
Purpose of the Study:
- To investigate the in vitro effects of external longitudinal oscillations on the stiffness of contracted ASM.
- To quantify changes in dynamic and static stiffness in response to varying oscillation parameters (frequency, amplitude, duration).
Main Methods:
- ASM tissues from pig tracheas were contracted using acetylcholine.
- Tissues were subjected to controlled external longitudinal oscillations at various frequencies and amplitudes.
- Muscle force changes were recorded to determine dynamic and static stiffness.
- A two-dimensional finite element model (FEM) was developed to generalize responses.
Main Results:
- Dynamic stiffness decreased with increasing oscillation frequency and/or amplitude.
- Static stiffness decreased with increasing excitation frequency and/or amplitude, plateauing above 25 Hz.
- Observed stiffness changes suggest a role for elasticity and mass inertia in dynamic ASM behavior.
Conclusions:
- External oscillations directly influence ASM contractile processes.
- Increased oscillation frequency and amplitude promote actin-myosin detachment, reducing muscle stiffness.
- Findings provide insights into the mechanical behavior of ASM under oscillatory loading.
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