Force-length dependence of arterial lamellar, smooth muscle, and myofilament orientations.
Force-length dependence of arterial lamellar, smooth muscle, and myofilament orientations.
复制标题
动脉板层、平滑肌和肌丝方向的力长度依赖性。
DOI：
10.1152/ajpheart.1987.253.5.h1141
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Murphy,RA
中科院分区：
文献类型：
--
作者：
Walmsley,JG;Murphy,RA
通过动脉组织的收缩元件产生的力可以受到它们与缩短的对齐的改变的影响。在完整的猪颈动脉或颈动脉条中，研究了平滑肌（SM）肌丝、内侧板和弹性板的方向和形态学随长度的变化。在等长收缩期间，将内膜-内侧组织条固定在相对于产生力的最佳长度（Lo）定义的长度（L）处。SM细胞在两个垂直平面上的平均取向在所有长度上都保持平行于组织的长轴，但角偏差的绝对值随着缩短而增加。组织延长与弹性板折叠减少有关。波度的这种降低通过拉伸指数（SI）来量化。超微结构观察表明，肌丝的绝对角偏差大于细胞排列。对于原位固定而收缩的动脉，SI在内膜周层中最少，在外周层中增加。从Lo缩短到0.6 Lo时，由于SM和肌丝角偏差增加，力产生能力的平均降低计算为7%。
Force generation by contractile elements of arterial tissue can be affected by alterations in their alignment with shortening. The orientation and morphometry of smooth muscle (SM) myofilaments, medial lamellae, and elastic laminae were examined as a function of length in intact swine carotid arteries or strips. Intimal-medial tissue strips were fixed during isometric contractions at lengths (L) defined with respect to the optimal length for force generation (Lo). The average orientation of SM cells in two perpendicular planes remained parallel to the long axis of the tissue at all lengths, but the absolute value of angular deviations increased with shortening. Tissue lengthening was associated with decreased folding of the elastic laminae. This decrease in waviness was quantified by a stretch index (SI). Ultrastructural observations indicated that the myofilament absolute angular deviation was greater than that for the cellular alignment. For arteries fixed in situ while constricted, SI was least in the periintimal laminae and increased in the peripheral laminae. The average decrease in force-generating capacity on shortening from Lo to 0.6 Lo attributed to increasing SM and myofilament angular deviations was calculated to be 7%.