Ishii N, Takahashi K
J Muscle Res Cell Motil. 1982 Mar;3(1):25-38. doi: 10.1007/BF00711878.
Single smooth muscle cells were isolated with an enzymatic dispersion procedure from the pedal retractor muscle (PRM) of Mytilus edulis. The isometric tension of the isolated cell was measured by photoelectrically recording the small, elastic displacement of one of the pair of micropipettes used to hold the ends of the cell by suction. Stimulation with a 0.1 ms rectangular current pulse elicited in the cell a twitch-like contraction which was comparable to that of the whole PRM in both time course an tension per unit cross-sectional area. The length-tension relation for maximal twitches showed that the isolated cell, like the whole PRM, can generate tension over a very wide range of lengths, that is from 0.2 to more that 2.0 Ls (where Ls is the shortest length which the resting cell assumes without any slack). No persistent tension was observed in the cell stretched up to 2.0 Ls, indicating that the passive tension observed in the whole PRM is caused by extracellular material.
采用酶分散法从蓝贻贝的足缩肌（PRM）中分离出单个平滑肌细胞。通过光电记录用于通过吸力固定细胞两端的一对微吸管之一的微小弹性位移，测量分离细胞的等长张力。用0.1毫秒的矩形电流脉冲刺激细胞，会引发类似抽搐的收缩，其时间进程和单位横截面积的张力与整个PRM的收缩相当。最大抽搐的长度-张力关系表明，分离的细胞与整个PRM一样，能够在非常宽的长度范围内产生张力，即从0.2到超过2.0 Ls（其中Ls是静息细胞在没有任何松弛情况下所呈现的最短长度）。在拉伸至2.0 Ls的细胞中未观察到持续张力，这表明在整个PRM中观察到的被动张力是由细胞外物质引起的。
