Load-dependent extracellular matrix organization in atrioventricular heart valves: differences and similarities

Autor: Jeffrey C. Milliken, Earl Steward, Aditi Sinha, S. Hamed Alavi, Arash Kheradvar
Rok vydání: 2015
Předmět:
Materials science
Time Factors
Biaxial load
Mechanotransduction
Swine
Physiology
Fibrillar Collagens
Image Processing
Medical Physiology
Stress
Mechanotransduction
Cellular
Fluorescence
collagen fibers
Imaging
Imaging
Three-Dimensional
Computer-Assisted
Models
Physiology (medical)
Image Processing
Computer-Assisted
Animals
cardiovascular diseases
Uniaxial load
biaxial load
Multiphoton
Microscopy
Fourier Analysis
Animal
Hemodynamics
Anatomy
Second Harmonic Generation Microscopy
Mechanical
Extracellular Matrix
Microscopy
Fluorescence
Multiphoton
uniaxial load
Cardiovascular System & Hematology
Models
Animal
Three-Dimensional
cardiovascular system
Mitral Valve
Stress
Mechanical
Tricuspid Valve
Cellular
Cardiology and Cardiovascular Medicine
mechanics
Extracellular matrix organization
Biomedical engineering
Zdroj: American journal of physiology. Heart and circulatory physiology, vol 309, iss 2
Alavi, SH; Sinha, A; Steward, E; Milliken, JC; & Kheradvar, A. (2015). Load-dependent extracellular matrix organization in atrioventricular heart valves: Differences and similarities. American Journal of Physiology-Heart and Circulatory Physiology, 309(2), H276-H284. doi: 10.1152/ajpheart.00164.2015. UC Irvine: Retrieved from: http://www.escholarship.org/uc/item/5sg065ms
Popis: © 2015 the American Physiological Society. The extracellular matrix of the atrioventricular (AV) valves’ leaflets has a key role in the ability of these valves to properly remodel in response to constantly varying physiological loads. While the loading on mitral and tricuspid valves is significantly different, no information is available on how collagen fibers change their orientation in response to these loads. This study delineates the effect of physiological loading on AV valves’ leaflets microstructures using Second Harmonic Generation (SHG) microscopy. Fresh natural porcine tricuspid and mitral valves’ leaflets (n = 12/valve type) were cut and prepared for the experiments. Histology and immunohistochemistry were performed to compare the microstructural differences between the valves. The specimens were imaged live during the relaxed, loading, and unloading phases using SHG microscopy. The images were analyzed with Fourier decomposition to mathematically seek changes in collagen fiber orientation. Despite the similarities in both AV valves as seen in the histology and immunohistochemistry data, the microstructural arrangement, especially the collagen fiber distribution and orientation in the stress-free condition, were found to be different. Uniaxial loading was dependent on the arrangement of the fibers in their relaxed mode, which led the fibers to reorient in-line with the load throughout the depth of the mitral leaflet but only to reorient in-line with the load in deeper layers of the tricuspid leaflet. Biaxial loading arranged the fibers in between the two principal axes of the stresses independently from their relaxed states. Unlike previous findings, this study concludes that the AV valves’ three-dimensional extracellular fiber arrangement is significantly different in their stress-free and uniaxially loaded states; however, fiber rearrangement in response to the biaxial loading remains similar.
Databáze: OpenAIRE
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