Transient intracellular calcium movement coupled with mechanical activity of smooth muscle.

我们先前展示了（J.J.P.35：1079，1985），即光滑的肌肉细胞中的无室内Ca（Guina Pig Jejunum）增加了机械反应的瞬态刺激。我们研究了使用Fura 2的单细胞的研究，该孤立的细胞是从Guiea猪中发现的，由Momose和Gomin描述的方法（J. Pharmaco动力学1：184）。Fura 2AM在37 ° C时30分钟内装入细胞，其中含有HEPES缓冲液的样本。该光倍增器设置了一个仅从一个单元格在显微镜阶段接收发射（470纳米）的光，在应用于电脉冲的应用时，从麝香开始的荧光光强度在一秒钟内立即释放到刺激到达最大值，然后在2秒钟后返回到原始水平。室内自由钙浓度估计为近似<10^（-7）> M，按<10^（-6）> M的顺序排列，其余的最大值，相应地。光强度变化的速率比以往任何时候都要快，因为在组织的准备中都要快。“承包的速度跟随的刺激比内向型Ca瞬态的慢得多。”在这里获得的结果，与前一个一起，建议内部存储的Ca可能扮演某些角色，以便在光滑肌肉细胞的机械激活中发挥某些角色。

We have shown previously(J.J.P.35:1079,1985) that, intracellular free Ca in smooth muscle cells(guina pig jejunum) increased transiently upon stimulation followed by the mechanical response. We explored this study to the single cell using Fura 2.The isolated cell was obtained from taenia coli of guiea pig according to the method described by Momose & Gomi in 1979(J.Pharmaco dynamics 1:184). Fura2 was loaded into the cell by incubating the sample in HEPES buffer containing Fura 2AM for 30 min at 37゜C. The photomultiplier was set to recieve the emission(470nm) light from only one cell on the stage of microscope.Upon application of electric pulse, intensity of fluorecence light from the muscle begun to increase immedately after application of stimulus reaching to the maximum within one sec and returned to the original level after 2 sec. Concentration of intracellular freeCa was estimated as approximately <10^(-7)> M and the order of <10^(-6)> M,at rest and the maximum,respectively. The rate of light intensity change was faster than that observed previously in the tissue preparation. The speed of contraction following the stimulation was much slower than that of intracellular Ca transient. The results obtained here,together with previous one,suggest that intracellulary stored Ca may play certain role for the mechanical activation of the smooth muscle cell.