Biaxial mechanical properties of passive and tetanized canine diaphragm.
Biaxial mechanical properties of passive and tetanized canine diaphragm.
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被动和强直犬隔膜的双轴机械特性。
DOI：
10.1152/ajpheart.1993.265.2.h469
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Yin,FC
中科院分区：
文献类型：
--
作者：
Strumpf,RK;Humphrey,JD;Yin,FC
膈肌的结构、血管供应和易于破伤风使膈肌成为评估主动和被动横纹肌多维力学特性的理想结构。我们开发了一种分离的，灌注的犬隔膜制剂，适用于评估静息状态和破伤风期间的双轴应力-应变关系。33个标本中的每一个都有一个宽而平坦的区域（大约3 x 3 cm），其中有一个单一的主要纤维方向。同时，在被动状态和强直收缩时，在相同的应变范围内，在纤维和垂直交叉纤维方向上施加相等的拉伸。在被动状态下表现出高度非线性行为，在两个方向上都有可拓极限。试件具有明显的各向异性，交叉纤维方向比纤维方向更硬（各方向应力回归线斜率平均为3.97）。33个试件中，有31个试件在跨纤维方向上刚度增大，1个试件在各向同性方向上刚度增大，1个试件在纤维方向上刚度增大。在破伤风过程中，各向异性的程度和分布发生了显著变化（回归斜率平均为1.08,18个试件在纤维方向上各向同性或变硬）。破坏覆盖每个表面的膜增加了拉伸性，降低了各向异性，从而表明这些膜承担了大部分被动载荷，并对完整隔膜的跨纤维刚度和各向异性有很大贡献。在表面膜破裂之前和之后，破伤风过程中交叉纤维应力仍然一致增加，这意味着垂直于纤维方向的主动力产生。（摘要删节250字）
The architecture, vascular supply, and ease of tetanization make the diaphragm an ideal structure in which to assess multidimensional mechanical properties of active and passive striated muscle. We developed an isolated, perfused canine diaphragm preparation suitable for the assessment of biaxial stress-strain relations in both the resting state and during tetanization. Each of 33 specimens had a wide, flat region (approximately 3 x 3 cm) wherein there was a single predominant fiber direction. Simultaneous, equal stretchings were imposed in the fiber and perpendicular cross-fiber directions over the same strain ranges in both the passive state and during tetanic contraction. Highly nonlinear behavior was seen in the passive state with a limit of extensibility in both directions. The specimens were also markedly anisotropic, with the cross-fiber direction being stiffer than the fiber direction (slopes of the regression line for the stresses in each direction averaged 3.97). Moreover, 31 of the 33 specimens were stiffer in the cross-fiber direction, one was isotropic, and one was stiffer in the fiber direction. During tetanization, the extent and distribution of anisotropy were significantly altered (regression slope averaged 1.08, and 18 specimens were now either isotropic or stiffer in the fiber direction). Disrupting the membranes covering each surface increased extensibility and decreased the anisotropy, thereby suggesting that these membranes bear most of the passive load and contribute greatly to the cross-fiber stiffness and anisotropy of the intact diaphragm. Both before and after disruption of the surface membranes, there was still a consistent increase in cross-fiber stress during tetanization, implying active force generation perpendicular to the fiber direction.(ABSTRACT TRUNCATED AT 250 WORDS)