Li Jiang, Zhao Jingbo, Liao Donghua, Gregersen Hans
Mech-Sense, Aalborg Hospital Science and Innovation Centre (AHSIC), Aalborg Hospital, Sdr. Skovvej 15, DK-9000 Aalborg, Denmark.
J Biomech. 2008 Aug 28;41(12):2667-72. doi: 10.1016/j.jbiomech.2008.06.017. Epub 2008 Jul 23.
It is difficult to measure gastrointestinal smooth muscle (SM) tone except in sphincter regions. Since tone affects the biomechanical properties, the aim of the present study was to evaluate intestinal SM tone by studying the morphometry and biomechanical properties with and without muscle tone. Circumferential rings of 0.8-1mm in width were cut from the rat duodenum, jejunum and ileum. Sectors were obtained by cutting the rings opposite to the mesentery. The rings and the sectors were immersed in physiological Krebs solution in order to maintain the tone and into Krebs solution without Ca++ and with EGTA to abolish the tone. The circumferences, area, the circularity and residual strain of the mucosal and serosal surfaces, opening angle, and opening angle tone/non-tone ratio were measured or computed. The tone affects the opening angle and residual strain in the intestinal sectors. The opening angle in the tissue sectors with tone was smaller (P<0.05) than those without tone in all three segments. The opening angle tone/non-tone ratio was 0.40+/-0.05, 0.43+/-0.06 and 0.36+/-0.11 for duodenum, jejunum and ileum, respectively, and did not differ among the three intestinal segments. The residual strain between sectors with and without SM tone differed in duodenal and jejunal mucosa and in the serosa of all three segments (P<0.05). The intestinal rings with tone showed axial variation for luminal area (P<0.001), for wall area (P<0.05), and for the mucosal and serosal residual strains (P<0.05). In conclusion, the intestinal mechanical properties are affected by intestinal SM tone. The tone can be evaluated by measuring the opening angle and residual strains of sectors in intestinal segments with and without SM tone.
除了在括约肌区域外，很难测量胃肠道平滑肌（SM）的张力。由于张力会影响生物力学特性，因此本研究的目的是通过研究有或无肌张力情况下的形态测量学和生物力学特性来评估肠道SM张力。从大鼠十二指肠、空肠和回肠切取宽度为0.8 - 1毫米的环形组织。通过在与肠系膜相对的位置切割环形组织获得扇形组织。将环形组织和扇形组织浸入生理 Krebs 溶液中以维持张力，并浸入不含 Ca++ 和含有 EGTA 的 Krebs 溶液中以消除张力。测量或计算黏膜和浆膜表面的周长、面积、圆形度和残余应变、开口角度以及开口角度张力/无张力比值。张力会影响肠道扇形组织的开口角度和残余应变。在所有三个节段中，有张力的组织扇形的开口角度均小于无张力的组织扇形（P<0.05）。十二指肠、空肠和回肠的开口角度张力/无张力比值分别为0.40±0.05、0.43±0.06和0.36±0.11，在三个肠道节段之间无差异。有和无SM张力的扇形组织之间的残余应变在十二指肠和空肠黏膜以及所有三个节段的浆膜中存在差异（P<0.05）。有张力的肠环在管腔面积（P<0.001）、壁面积（P<0.05）以及黏膜和浆膜残余应变方面显示出轴向变化（P<0.05）。总之，肠道机械特性受肠道SM张力影响。可以通过测量有和无SM张力的肠道节段扇形组织的开口角度和残余应变来评估张力。
