Stress and strain analysis of contractions during ramp distension in partially obstructed guinea pig jejunal segments.
Stress and strain analysis of contractions during ramp distension in partially obstructed guinea pig jejunal segments.
复制标题
部分阻塞的豚鼠空肠段斜坡扩张期间收缩的应力和应变分析。
DOI：
10.1016/j.jbiomech.2011.05.017
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发表时间：
2011
影响因子：
2.4
通讯作者：
Gregersen,Hans
中科院分区：
文献类型：
--
作者：
Zhao,Jingbo;Liao,Donghua;Yang,Jian;Gregersen,Hans
先前的研究已经证明了梗阻近端肠的形态学和生物力学重塑。本研究的目的是获得部分梗阻的豚鼠空肠段的应力和应变阈值开始收缩和最大收缩应力和应变。在雄性豚鼠的空肠中段手术造成部分梗阻和假手术。动物存活2、4、7和14天。未手术的动物作为正常对照。这些节段用于空载状态、零应力状态和扩张分析。在含有37°C Krebs溶液的器官浴中将节段充气至10 cmH2O压力，并监测外径变化。根据直径、压力和零应力状态数据计算收缩阈值和最大收缩时的应力和应变。在收缩阈值下测定杨氏模量。梗阻肠段肌层厚度增加达300%。与假梗阻组和正常组相比，梗阻7d后，收缩应力阈值、最大收缩应力和收缩阈值时的杨氏模量增加，而应变阈值和最大收缩应变降低（P<0.05和0.01）。总之，在部分梗阻的肠段中，需要更大的扩张力来引起收缩，这可能是由于组织重塑。产生较高的收缩应力，收缩变形（应变）变小。
Previous studies have demonstrated morphological and biomechanical remodeling in the intestine proximal to an obstruction. The present study aimed to obtain stress and strain thresholds to initiate contraction and the maximal contraction stress and strain in partially obstructed guinea pig jejunal segments. Partial obstruction and sham operations were surgically created in mid-jejunum of male guinea pigs. The animals survived 2, 4, 7 and 14 days. Animals not being operated on served as normal controls. The segments were used for no-load state, zero-stress state and distension analyses. The segment was inflated to 10cmH2O pressure in an organ bath containing 37°C Krebs solution and the outer diameter change was monitored. The stress and strain at the contraction threshold and at maximum contraction were computed from the diameter, pressure and the zero-stress state data. Young's modulus was determined at the contraction threshold. The muscle layer thickness in obstructed intestinal segments increased up to 300%. Compared with sham-obstructed and normal groups, the contraction stress threshold, the maximum contraction stress and the Young's modulus at the contraction threshold increased whereas the strain threshold and maximum contraction strain decreased after 7 days obstruction (P<0.05 and 0.01). In conclusion, in the partially obstructed intestinal segments, a larger distension force was needed to evoke contraction likely due to tissue remodeling. Higher contraction stresses were produced and the contraction deformation (strain) became smaller.