Zhao Jingbo, Liao Donghua, Gregersen Hans
Center of Excellence in Visceral Biomechanics and Pain, Aalborg Hospital, and Center of Sensory-Motor Interaction, Aalborg University, DK-9220 Aalborg, Denmark.
J Diabetes Complications. 2007 Jan-Feb;21(1):34-40. doi: 10.1016/j.jdiacomp.2005.12.001.
Diabetes mellitus induces remodeling of the morphology and mechanical properties in the gastrointestinal tract. This study aimed to investigate the histomorphometric and biomechanical remodeling of esophagus in the diabetic type 2 model Goto-Kakizaki (GK) rats. Five male diabetic GK rats and five male nondiabetic Wistar rats were used in this study. The mechanical test was performed in vitro where the whole esophagus was stretched to its in situ length and distended with pressures up to 10 cm H2O using a ramp distension protocol. The pressure and outer diameter were recorded. Circumferential stress (force per area) and strain (deformation) were computed from the diameter and pressure data using the zero-stress state as reference. The zero-stress state was obtained by cutting esophageal rings radially. This caused the rings to open up into a sector. The thickness, area, and the opening angle were measured from the digitized images. The layer circumference, thickness, and area were measured from histological slides. The collagen fraction was determined from histological slides with Van Gieson stain. Diabetes induced pronounced morphometric changes, e.g., the wall thickness and wall cross-sectional area significantly increased in the GK rats (P<.01). Histologically, the circumference, thickness, and area of the muscle layer and the collagen fraction of mucosa-submucosa layer were significantly increased in the GK rats (P<.01). The opening angle, outer residual strain, and residual strain difference to wall thickness ratio decreased significantly in the GK rats (P<.05 and P<.01). Furthermore, the circumferential stiffness of the esophagus is significantly higher in the GK rats than in the normal rats (P<.01). In conclusion, histomorphometric and biomechanical remodeling is a feature of the esophageal wall in GK rats.
糖尿病会导致胃肠道形态和力学性能的重塑。本研究旨在调查2型糖尿病模型Goto-Kakizaki(GK)大鼠食管的组织形态计量学和生物力学重塑情况。本研究使用了5只雄性糖尿病GK大鼠和5只雄性非糖尿病Wistar大鼠。体外进行力学测试,将整个食管拉伸至其原位长度,并使用斜坡扩张方案以高达10 cm H2O的压力进行扩张。记录压力和外径。以零应力状态为参考,根据直径和压力数据计算周向应力(单位面积力)和应变(变形)。通过径向切割食管环获得零应力状态。这使得环打开成一个扇形。从数字化图像中测量厚度、面积和开口角度。从组织学切片中测量层周长、厚度和面积。用Van Gieson染色从组织学切片中测定胶原分数。糖尿病引起了明显的形态计量学变化,例如GK大鼠的壁厚和壁横截面积显著增加(P<0.01)。组织学上,GK大鼠的肌层周长、厚度和面积以及黏膜下层的胶原分数显著增加(P<0.01)。GK大鼠的开口角度、外残余应变和残余应变与壁厚比值显著降低(P<0.05和P<0.01)。此外,GK大鼠食管的周向刚度显著高于正常大鼠(P<0.01)。总之,组织形态计量学和生物力学重塑是GK大鼠食管壁的一个特征。