Zhao Jingbo, Yang Jian, Vinter-Jensen Lars, Zhuang Fengyuan, Gregersen Hans
Center for Sensory-Motor Interaction, Aalborg University, and Department A, Aalborg Hospital, Denmark.
Biorheology. 2002;39(6):719-33.
Morphometric and passive biomechanical properties were studied in isolated segments of the duodenum, jejunum and ileum in 22 EGF-treated rats and 12 control rats. The rats were allocated to groups with EGF treatment for 2, 4, 7, and 14 days (n = 6 for each EGF treatment group except n = 4 for the 14 days group) or saline treatment (n = 3 for each group). The intestinal segments were pressurized with Krebs solution from 0 to 8 cmH2O for duodenum and 0 to 6 cmH2O for jejunum and ileum using a ramp distension protocol. The diameter and length were recorded at different pressure levels. Circumferential and longitudinal stresses (force per area) and strains (deformation) were computed from the length, diameter, pressure and the zero-stress state data. EGF treatment was associated with pronounced morphometric changes, e.g., the wall thickness, wall area, and the circumferential lengths significantly increased during EGF treatment in all intestinal segments (P < 0.05). Histological analysis showed that the thickness and area of the layers increased after EGF treatment. With respect to the biomechanical data, the opening angle increased in all segments during EGF treatment with the highest value in the 14 days EGF treatment group (P < 0.05). The same result was found for residual strain and the residual strain gradient through the intestinal wall. Linear regression analysis demonstrated that the opening angle mainly depended on the mucosa thickness and area. Furthermore, the circumferential stiffness increased in the duodenum and decreased in the jejunum and ileum during EGF treatment. A plateau was reached after 7 days where after it started to normalize (P < 0.01). In the longitudinal direction, all intestinal segments became stiffer after EGF treatment for 7 days. After 14 days the curve started to normalize in duodenum and jejunum but not in the ileum.
在22只接受表皮生长因子（EGF）治疗的大鼠和12只对照大鼠中，对十二指肠、空肠和回肠的离体节段进行了形态测量和被动生物力学特性研究。将大鼠分为接受EGF治疗2天、4天、7天和14天的组（除14天组n = 4外，每个EGF治疗组n = 6）或生理盐水治疗组（每组n = 3）。使用斜坡扩张方案，用 Krebs 溶液对肠段进行加压，十二指肠从0至8 cmH₂O，空肠和回肠从0至6 cmH₂O。记录不同压力水平下的直径和长度。根据长度、直径、压力和零应力状态数据计算周向和纵向应力（单位面积的力）及应变（变形）。EGF治疗与明显的形态测量变化相关，例如，在所有肠段的EGF治疗期间，壁厚、壁面积和周向长度显著增加（P < 0.05）。组织学分析表明，EGF治疗后各层的厚度和面积增加。关于生物力学数据，在EGF治疗期间所有节段的开口角度均增加，在14天EGF治疗组中达到最高值（P < 0.05）。肠壁的残余应变和残余应变梯度也得到相同结果。线性回归分析表明，开口角度主要取决于黏膜厚度和面积。此外，在EGF治疗期间，十二指肠的周向刚度增加，空肠和回肠的周向刚度降低。7天后达到平台期，之后开始恢复正常（P < 0.01）。在纵向方向上，EGF治疗7天后所有肠段都变得更硬。14天后，十二指肠和空肠的曲线开始恢复正常，但回肠未恢复。
