Duch B U, Petersen J A, Vinter-Jensen L, Gregersen H
Department of Surgical Gastroenterology L, Aarbus University Hospital, Denmark.
Acta Physiol Scand. 1996 Jun;157(2):157-63. doi: 10.1046/j.1365-201X.1996.503248000.x.
The aim was to study the passive biomechanical wall properties in the isolated duodenum, jejunum and ileum of the rat. The organ bath contained a Krebs-Ringer solution with 10(-2) M MgCl2 to abolish smooth muscle contractile activity. Stepwise inflation of an intraluminal balloon, in which the cross-sectional area (CSA) was measured, provided the distension stimulus. The circumferential wall stress-strain distributions were computed from steady-state values of these measurements and the unstressed wall thickness was measured in order to evaluate the passive elastic properties. The CSAs measured increased from duodenum to jejunum and to ileum (P < 0.001). At the highest applied pressure load the CSA was 16.64 +/- 0.46 mm2 for the duodenum, 18.70 +/- 0.53 mm2 for the jejunum and 21.73 +/- 0.49 mm2 for the ileum. The wall thickness was 0.19 +/- 0.01, 0.25 +/- 0.01 and 0.28 +/- 0.02 mm, in duodenum, jejunum and ileum, respectively (P < 0.01). All segments showed stress-strain distributions that were exponential by nature. Applying the function Y = exp (a + bX) gave a median determination coefficient of 0.98 (quartiles 0.96-0.99). The duodenum was significantly stiffer than the two other segments. The values of a and b were 2.03 +/- 0.11 and 14.82 +/- 1.81, 1.39 +/- 0.20 and 13.15 +/- 1.42, and 1.13 +/- 0.13 and 10.69 +/- 0.65 for the duodenum, jejunum and ileum, respectively. The a differed between the duodenum and the other segments (P < 0.001). whereas the b differed only between the duodenum and ileum (P < 0.005). In conclusion, differences in the luminal CSA, wall thickness and elastic properties were found between the duodenum, jejunum and ileum.
目的是研究大鼠离体十二指肠、空肠和回肠的被动生物力学壁特性。器官浴槽中含有含10(-2)M氯化镁的克雷布斯-林格溶液，以消除平滑肌收缩活性。通过逐步充胀腔内气囊（测量其横截面积（CSA））提供扩张刺激。根据这些测量的稳态值计算圆周壁应力-应变分布，并测量无应力壁厚度以评估被动弹性特性。测量得到的CSA从十二指肠到空肠再到回肠逐渐增加（P < 0.001）。在最高施加压力负荷下，十二指肠的CSA为16.64±0.46平方毫米，空肠为18.70±0.53平方毫米，回肠为21.73±0.49平方毫米。十二指肠、空肠和回肠的壁厚度分别为0.19±0.01、0.25±0.01和0.28±0.02毫米（P < 0.01）。所有节段的应力-应变分布本质上均为指数分布。应用函数Y = exp (a + bX)得到的中位数决定系数为0.98（四分位数为0.96 - 0.99）。十二指肠比其他两个节段明显更硬。十二指肠、空肠和回肠的a值分别为2.03±0.11和14.82±1.81、1.39±0.20和13.15±1.42、1.13±0.13和10.69±0.65。十二指肠与其他节段的a值不同（P < 0.001），而b值仅在十二指肠和回肠之间不同（P < 0.005）。总之，十二指肠、空肠和回肠之间在管腔CSA、壁厚度和弹性特性方面存在差异。
