Yang Jian, Zhao Jingbo, Liao Donghua, Gregersen Hans
Centre of Excellence in Visceral Biomechanics and Pain, Aalborg Hospital and Centre of Sensory-Motor Interaction, Aalborg University, DK-9100 Aalborg, Nord Jylland, Denmark.
J Biomech. 2006;39(5):894-904. doi: 10.1016/j.jbiomech.2005.01.022.
Passive biomechanical properties in term of the stress-strain relationship and the shear modulus were studied in separated muscle layer and mucosa-submucosa layer in the oesophagus of normal and STZ (streptozotocin)-induced diabetic rats. The mucosa-submucosa and muscle layers were separated using microsurgery and studied in vitro using a self-developed test machine. Stepwise elongation and inflation plus continuous twist were applied to the samples. A constitutive equation based on a strain energy function was used for the stress-strain analysis. Five material constants were obtained for both layers. The mucosa-submucosa layer was significantly stiffer than the muscle layer in longitudinal, circumferential and circumferential-longitudinal shear direction. The mechanical constants of the oesophagus show that the oesophageal wall was anisotropic, the stiffness in the longitudinal direction was higher than in the circumferential direction in the intact oesophagus (P < 0.001) and in the muscle layer (P < 0.05). Diabetes-induced pronounced increase in the outer perimeter, inner perimeter and lumen area in both the muscle and mucosa-submucosa layer. The growth of the mucosa-submucosa layer (P < 0.001) was more pronounced than the muscle layer (P < 0.05). Furthermore, the circumferential stiffness of the mucosa-submucosa layer increased 28 days after STZ treatment. In conclusion, the oesophagus is a non-homogeneous anisotropic tube. Thus, the mechanical properties differed between layers as well as in different directions. Morphological and biomechanical remodelling is prominent in the diabetic oesophagus.
在正常大鼠和链脲佐菌素（STZ）诱导的糖尿病大鼠的食管中，研究了分离的肌肉层和黏膜-黏膜下层在应力-应变关系和剪切模量方面的被动生物力学特性。使用显微外科技术分离黏膜-黏膜下层和肌肉层，并使用自行研制的测试机器进行体外研究。对样本施加逐步伸长、膨胀以及连续扭转。基于应变能函数的本构方程用于应力-应变分析。两层均获得了五个材料常数。黏膜-黏膜下层在纵向、周向和周向-纵向剪切方向上均显著比肌肉层更硬。食管的力学常数表明食管壁是各向异性的，完整食管（P < 0.001）和肌肉层（P < 0.05）中纵向的刚度高于周向。糖尿病导致肌肉层和黏膜-黏膜下层的外周、内周和管腔面积显著增加。黏膜-黏膜下层的生长（P < 0.001）比肌肉层（P < 0.05）更明显。此外，STZ治疗28天后黏膜-黏膜下层的周向刚度增加。总之，食管是一个非均匀各向异性的管道。因此，各层之间以及不同方向上的力学特性存在差异。糖尿病食管中形态学和生物力学重塑很显著。
