Watanabe K, Suzuki A
Department of Animal Production Sciences, Graduate School of Agricultural Science, Tohoku University, Sendai-shi, Japan.
Okajimas Folia Anat Jpn. 1999 Dec;76(5):203-19. doi: 10.2535/ofaj1936.76.5_203.
Muscle spindles are not always distributed more in postural muscles with many slow-twitch-oxidative (SO) myofibers than in locomotory muscles with few SO myofibers. The purpose of present study was to examine the distribution, density, and structure of muscle spindles in the vastus intermedius muscle: an antigravity muscle and the peroneus longus muscle: a locomotory muscle in the sheep. Muscle spindles were reconstructed from serial sections at 300 microns intervals throughout the muscles. Myofiber types were classified into SO, fast-twitch-oxidative-glycolytic, and fast-twitch-glycolytic myofibers by differences in histochemical reactivity. No significant difference in the density of muscle spindles (DMS) existed between the vastus intermedius (DMS: 5.3) and peroneus longus (DMS: 5.7) muscles. The muscle spindles were distributed more in the distal portion than in the proximal portion of the vastus intermedius muscle. The muscle spindles were distributed in the proximal and middle portion but hardly in the distal portion of the peroneus longus muscle. Muscle spindles were classified into simple, tandem, and compound muscle spindles. Most of the muscle spindles were the simple type. The differences in size of the muscle spindle and numbers of the intrafusal myofibers were not significant between the two muscles. The results show that the density and structure of the muscle spindles do not differ between the postural and locomotory muscles in the sheep.
肌梭并不总是在具有许多慢肌纤维氧化型（SO）肌纤维的姿势肌中比在具有较少SO肌纤维的运动肌中分布更多。本研究的目的是检查绵羊股中间肌（一种抗重力肌）和腓骨长肌（一种运动肌）中肌梭的分布、密度和结构。通过每隔300微米的连续切片重建整个肌肉中的肌梭。通过组织化学反应的差异将肌纤维类型分为SO、快肌纤维氧化糖酵解型和快肌纤维糖酵解型。股中间肌（肌梭密度：5.3）和腓骨长肌（肌梭密度：5.7）之间的肌梭密度（DMS）没有显著差异。肌梭在股中间肌的远端部分比近端部分分布更多。肌梭分布在腓骨长肌的近端和中间部分，但在远端部分几乎没有。肌梭分为简单型、串联型和复合型肌梭。大多数肌梭为简单型。两种肌肉之间肌梭大小和梭内肌纤维数量的差异不显著。结果表明，绵羊姿势肌和运动肌中肌梭的密度和结构没有差异。
