Study of intracellular calcium movement by time resolved image processing method.

已知肌肉收缩由细胞内钙离子浓度的增加触发。该项目的目的是观察是否钙浓度均匀增加，在一个单一的骨骼肌纤维使用视频增强显微镜系统和图像处理器。利用发光蛋白水母发光蛋白作为钙指示剂，同时记录了水母发光的光倍增信号和图像。1.将水母发光蛋白注射到单个骨骼肌纤维中，并开始抽搐。在注射水母发光蛋白的区域观察到发光点。如果添加几个抽搐的图像，则在水母发光蛋白注射区域中没有观察到显著的亮度差异。2.在强直的骨骼肌纤维（40 Hz，1 sec）中，张力持续，并且在水母发光蛋白注射区域中添加几个图像后，没有识别到亮度的显著差异。当肌节从2.4 m变为3.6 m时，也得到类似的结果<micrn><micrn>。已知咖啡因会从肌浆网释放钙，导致挛缩，出现在制备物表面的发光点扩散到纤维中心。最后，水母发光蛋白负载区域变得均匀明亮。这些结果表明，在显微镜和视频分辨率的限制下，生理激活不会引起细胞内钙离子浓度的不均匀性，而咖啡因扩散到纤维中会引起钙离子释放的不均匀性。引起非均匀激活的条件及其意义有待进一步研究

Muscle contraction is known to be triggered by an increase of intracellular calcium ion concentration. The aim of the project was to observe whether calcium concentration increases homogeneously in a single skeleral muscle fiber using video-intensified microscopy system and image processor. Bioluminescent photoprotein, aequorin, was used as a calcium indicator, and phtomultiplier signal and image of aequorin luminescence were simultaneously recorded. 1. Aequorin was injected into a single skeletal muscle fiber and twitch was initiated. Luminescent spots were observed in the area where aequorin was injected. If several images of twitches were added, no substantial difference of brightness was observed in the aequorin injected area. 2. In tetanized skeletal muscle fibers (40 Hz, 1 sec), tension was sustained and no significant difference of brightness was recognized after adding several images in the aequorin injected area. Similar result was obtained when the sarcomere was changed form 2.4<micrn>m to 3.6<micrn>m. Caffeine known to release calcium from sarcoplasmic reticulum caused contracture, and luminescent spots which appeared in the surface of the preparation spreaded into the center of the fiber. Finally, the aequorin loaded area became bright homogeneously. These results indicate that physiological activation dose not cause inhomogeneity of intracellular calcium concentration under the limitation of microscopic and video resolution and that caffeine which diffuses into the fiber causes inhomogeneous calcium ion release. Further study is required to clarify the condition which causes inhomogeneous activation and its significance