Devine C E, Somlyo A P
J Cell Biol. 1971 Jun;49(3):636-49. doi: 10.1083/jcb.49.3.636.
Two sets of myofilaments were demonstrated after incubation of strips of rabbit portal-anterior mesenteric vein under moderate stretch in a physiological salt solution. Thick filaments had a mean diameter of 18 nm and reached a maximum length of 1.4 microm with a mean length of 0.61 microm. In transverse sections, 2.5-5 nm particles were resolved as subunits of the thick filaments. Thin filaments had an average diameter of 8.4 nm and generally conformed to the structure believed to represent actin filaments in smooth and striated muscles. In the areas of maximum concentration there were 160-328 thick filaments/microm(2) and the lowest ratio of thin to thick filaments was 12:1. Thick filaments were present in approximately equal numbers in vascular smooth muscle relaxed by theophylline, in Ca(++)-free solution, or contracted by norepinephrine. The same preparatory procedures used with vascular smooth muscle also enabled us to visualize thick filaments in guinea pig and rabbit taenia coli and vas deferens.
在生理盐溶液中对兔门静脉 - 肠系膜前静脉条带进行适度拉伸孵育后,观察到两组肌丝。粗肌丝平均直径为18纳米,最大长度达1.4微米,平均长度为0.61微米。在横切面上,2.5 - 5纳米的颗粒可分辨为粗肌丝的亚基。细肌丝平均直径为8.4纳米,总体上符合被认为代表平滑肌和横纹肌中肌动蛋白丝的结构。在浓度最高的区域,每平方微米有160 - 328根粗肌丝,细肌丝与粗肌丝的最低比例为12:1。在被茶碱松弛、处于无钙溶液中或被去甲肾上腺素收缩的血管平滑肌中,粗肌丝数量大致相等。用于血管平滑肌的相同制备程序也使我们能够在豚鼠和兔的结肠带和输精管中观察到粗肌丝。