Capillary tortuosity in skeletal muscles of mammals depends on muscle contraction.
Capillary tortuosity in skeletal muscles of mammals depends on muscle contraction.
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哺乳动物骨骼肌中的毛细血管曲折取决于肌肉收缩。
DOI：
10.1152/jappl.1989.66.3.1436
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Weibel,ER
中科院分区：
文献类型：
--
作者：
Mathieu-Costello,O;Hoppeler,H;Weibel,ER
比较了不同大小和/或不同有氧能力的哺乳动物(狗、山羊、小马和小牛)后肢肌肉的毛细血管取向(各向异性)。肌节长度1.5~2.7微米，采用血管灌注法固定。使用两组截面(0和90度)上每纤维横截面积上的毛细血管计数与肌纤维轴的比率来估计毛细血管各向异性，以及与1)横切面上的毛细血管计数(评估肌肉毛细血管性能的常用参数)和2)每纤维体积的毛细血管长度(即毛细血管长度密度)相关的系数c(K，0)。随着肌纤维的缩短，平行于肌纤维轴的毛细血管取向显著降低。在肌节长度为2.69微米(犬股中肌)和1.52微米(犬腓肠肌)的肌肉中，毛细血管弯曲和分支分别使毛细血管长度密度增加7%和%。在这项研究中获得的数据与先前用同样的方法在扩张和收缩的大鼠肌肉中证明的毛细血管各向异性和肌节长度之间的关系高度一致。哺乳动物运动肌的毛细血管各向异性与肌节长度呈曲线相关。无论是身体大小、运动能力还是有氧能力，都没有发现毛细血管弯曲程度的系统性差异。毛细血管弯曲是纤维缩短的结果，而不是组织氧气需求的指标。
Capillary orientation (anisotropy) was compared in hindlimb muscles of mammals of different size and/or different aerobic capacity (dog, goat, pony, and calf). All muscles were fixed by vascular perfusion at sarcomere lengths ranging from 1.5 to 2.7 micron. The ratios of capillary counts per fiber cross-sectional area on two sets of sections (0 and 90 degrees) to the muscle fiber axis were used to estimate capillary anisotropy and the coefficient c(K,0) relating 1) capillary counts on transverse sections (a commonly used parameter to assess muscle capillarity) and 2) capillary length per volume of fiber (i.e., capillary length density). Capillary orientation parallel to the muscle fiber axis decreased substantially with muscle fiber shortening. In muscles fixed at sarcomere lengths of 2.69 microns (dog vastus intermedius) and 1.52 microns (dog gastrocnemius), capillary tortuosity and branching added 7 and 64%, respectively, to capillary length density. The data obtained in this study are highly consistent with the previously demonstrated relationship between capillary anisotropy and sarcomere length in extended vs. contracted rat muscles, by use of the same method. Capillary anisotropy in mammalian locomotory muscles is curvilinearly related to sarcomere length. No systematic difference was found in capillary tortuosity with either body size, athletic ability, or aerobic capacity. Capillary tortuosity is a consequence of fiber shortening rather than an indicator of the O2 requirements of the tissue.