CONTRACTILE APPARATUS OF VASCULAR SMOOTH-MUSCLE - INTERMEDIATE HIGH-VOLTAGE STEREO ELECTRON-MICROSCOPY
CONTRACTILE APPARATUS OF VASCULAR SMOOTH-MUSCLE - INTERMEDIATE HIGH-VOLTAGE STEREO ELECTRON-MICROSCOPY
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DOI：
10.1016/s0022-2836(75)80098-2
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发表时间：
1975-01-01
影响因子：
5.6
通讯作者：
SOMLYO, AP
中科院分区：
文献类型：
--
作者：
ASHTON, FT;SOMLYO, AV;SOMLYO, AP
兔门静脉-肠系膜前静脉平滑肌的中高压立体电镜显示，平滑肌纤维粗，长2.2 μm，末端呈锥形。在连续的横截面中，三至五根粗丝的组在同一截面内结束或开始。中间（10 nm直径）丝与致密体，如在以前的研究中所指出的，从来没有看到在粗丝的子结构。肌动蛋白丝被发现插入细胞质和质膜结合的致密体。尽管平滑肌中肌球蛋白的浓度低得多，但平滑肌中粗丝的长度比横纹肌中长，并且它们在纤维内的“平行排列”可能有助于平滑肌产生与横纹肌相等或更大的张力的能力。
Intermediate high voltage stereo electron microscopy of rabbit portal-anterior mesenteric vein smooth muscle showed that thick filaments are 2·2 μm long and have tapered ends. In serial transverse sections, groups of three to five thick filaments end or begin within the same section. The intermediate (10 nm diameter) filaments were associated with dense bodies, as noted in previous studies, and were never seen within the substructure of the thick filaments. Actin filaments were found inserting on both cytoplasmic and plasma membrane-bound dense bodies. The greater length of the thick filaments in smooth than in striated muscles and their “parallel arrangement” within the fiber could contribute to the ability of smooth muscle to develop equal or greater tension than striated muscle, in spite of the much lower concentration of myosin in smooth muscle.