Tissue contribution to the mechanical features of diaphragmatic initial lymphatics
Tissue contribution to the mechanical features of diaphragmatic initial lymphatics
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DOI：
10.1113/jphysiol.2010.196204
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发表时间：
2010-10-15
影响因子：
5.5
通讯作者：
Negrini, Daniela
中科院分区：
文献类型：
--
作者：
Moriondo, Andrea;Boschetti, Federica;Negrini, Daniela
在6只麻醉、神经肌肉阻滞和机械通气的大鼠中，研究了初始淋巴壁和周围组织的力学特性在支持淋巴形成和/或进展中的作用。胸骨正中开胸后，体位显微镜在胸膜横膈膜表面发现间皮下初始淋巴管。通过在血管周围固定两根手术线，使血管保持2.5毫米的距离，制备了一个“体内”淋巴段。将两个玻璃微移液管插入腔内，一个用于腔内注射4.6 nl盐水丸，另一个用于液压（P（淋巴））记录。血管壁的顺应性（C（淋巴））被计算为描述节段体积变化作为注射后P（淋巴）变化函数的曲线的斜率。两个浅表淋巴管群的C（淋巴管）差异显著（6.7 +/- 1.6和1.5 +/- 0.4 nl mmHg-1（平均+/- s.e.m.）， P < 0.001）。另外7只大鼠经单轴拉伸试验测得膈组织条的平均弹性模量为1.7 +/- 0.3 MPa。完全被各向同性组织包围的初始淋巴管的C（淋巴）计算值为0.068 nl mmHg-1，即比间皮下淋巴管低两个数量级。对淋巴壁应力分布的建模表明，柔顺的血管可能充当容纳大量吸收液体的储存器，而壁较硬的淋巴管则利用组织应力向淋巴管腔更有效的机械传递的优势，推动液体通过淋巴管的管腔。
The role of the mechanical properties of the initial lymphatic wall and of the surrounding tissue in supporting lymph formation and/or progression was studied in six anaesthetized, neuromuscularly blocked and mechanically ventilated rats. After mid-sternal thoracotomy, submesothelial initial lymphatics were identified on the pleural diaphragmatic surface through stereomicroscopy. An 'in vivo' lymphatic segment was prepared by securing two surgical threads around the vessel at a distance of similar to 2.5 mm leaving the vessel in place. Two glass micropipettes were inserted into the lumen, one for intraluminar injections of 4.6 nl saline boluses and one for hydraulic pressure (P(lymph)) recording. The compliance of the vessel wall (C(lymph)) was calculated as the slope of the plot describing the change in segment volume as a function of the post-injection P(lymph) changes. Two superficial lymphatic vessel populations with a significantly different C(lymph) (6.7 +/- 1.6 and 1.5 +/- 0.4 nl mmHg-1 (mean +/- s.e.m.), P < 0.001) were identified. In seven additional rats, the average elastic modulus of diaphragmatic tissue strips was determined by uniaxial tension tests to be 1.7 +/- 0.3 MPa. C(lymph) calculated for an initial lymphatic completely surrounded by isotropic tissue was 0.068 nl mmHg-1, i.e. two orders of magnitude lower than in submesothelial lymphatics. Modelling of stress distribution in the lymphatic wall suggests that compliant vessels may act as reservoirs accommodating large absorbed fluid volumes, while lymphatics with stiffer walls serve to propel fluid through the lumen of the lymphatic vessel by taking advantage of the more efficient mechanical transmission of tissue stresses to the lymphatic lumen.