Gao F, Liao D, Drewes A M, Gregersen H
Mech-Sense, Department of Gastroenterology, Aalborg Hospital, Aalborg, Denmark.
Neurogastroenterol Motil. 2009 Sep;21(9):914-e68. doi: 10.1111/j.1365-2982.2009.01314.x. Epub 2009 Apr 29.
Systemic sclerosis (SS) is a connective tissue disease that involves the gastrointestinal tract. Previous experiments have shown abnormal intestinal motility, dilatation, wall stiffening and impaired smooth muscle function. Consequently, understanding the association between intestinal wall mechanics, structure and function is important. The aim was to establish a model for differentiating the biomechanical remodelling of elastin, collagen and smooth muscle in the duodenum in SS patients. A duodenal distension protocol was used in six patients and five healthy controls. A theoretical model for evaluating the mechanical contributions of elastin, collagen and smooth muscle tone was established. The tension-strain curves computed from pressure and cross-sectional area data were analysed. The elastic modulus of elastin, the relationship between the collagen recruitment, collagen density and the active tension were calculated. The model fitted the clinical data well. The material constant for elastin in the patients was 30% lower than in the control group (P = 0.005). More collagen was recruited in patients than in healthy volunteers. Eighty percent of the collagen fibres were recruited at stretch ratio 0.85-2.26 (1.61 averaged) in patients and at the stretch ratio 2.55-3.73 (2.97 averaged) in healthy controls. The maximum active muscle tension and the corresponding strain were lowest in the patients (P = 0.01). The model can be used to determine the contribution of tissue components to the mechanical behaviour of duodenum. The stiffer wall in patient was due to the small stretch ratio for the maximum collagen recruitment but the muscle activity was also impaired.
系统性硬化症（SS）是一种累及胃肠道的结缔组织疾病。既往实验显示肠道运动异常、扩张、肠壁僵硬及平滑肌功能受损。因此，了解肠壁力学、结构与功能之间的关联很重要。目的是建立一个模型，以区分SS患者十二指肠中弹性蛋白、胶原蛋白和平滑肌的生物力学重塑。对6例患者和5名健康对照者采用十二指肠扩张方案。建立了一个评估弹性蛋白、胶原蛋白和平滑肌张力的力学贡献的理论模型。分析了根据压力和横截面积数据计算出的张力-应变曲线。计算了弹性蛋白的弹性模量、胶原蛋白募集、胶原蛋白密度与主动张力之间的关系。该模型与临床数据拟合良好。患者弹性蛋白的材料常数比对照组低30%（P = 0.005）。患者比健康志愿者募集了更多的胶原蛋白。患者中80%的胶原纤维在拉伸比0.85 - 2.26（平均1.61）时被募集，而健康对照者在拉伸比2.55 - 3.73（平均2.97）时被募集。患者的最大主动肌肉张力及相应应变最低（P = 0.01）。该模型可用于确定组织成分对十二指肠力学行为的贡献。患者肠壁更硬的原因是最大胶原蛋白募集时的拉伸比小，但肌肉活性也受损。
