Sex Differences in the Mechanical Behavior of the Decellularized Rat Left Ventricle

Abstract

There are fundamental differences in the size and performance of male and female hearts. Even after adjustments for height and body surface area, the left ventricle of a healthy male is larger in both volume and mass [1]. There are differences in contractile performance between papillary muscle from male and female rats with male rats showing slower responses in both isometric and isotonic tests [2]. It is less clear, however, whether the underlying structure or mechanical properties vary between sexes as well. Of particular interest to us is the extracellular matrix (ECM) of the ventricular wall, which provides structural stability to the heart. This matrix can be isolated by perfusion decellularization [3].

Automatic Segmentation of Mechanically Inhomogeneous Tissues Based on Deformation Gradient Jump

“…The model uses four parameters; the direction ( μ ) and degree ( κ ) of fiber orientation and the small-strain stiffness ( A ) and nonlinearity ( B ) of the fibers. Simulation parameters were selected based on previous fits of the NFSM to data from rat myocardium [73] and cadaveric bladder wall [69]. For the first set of simulations, a cruciform sample was generated with a central triangular shaped inclusion; the inclusion varied from the bulk sequentially in prescribed fiber orientation ( μ bulk =20° and μ inclusion =80°), strength of alignment ( κ bulk =1.5 and κ inclusion = 6.0), stiffness ( A bulk = 5 kpa and A inclusion = 20 kpa ), and nonlinearity ( B bulk = 12 kpa and B inclusion = 48 kpa ).…”