Study on molecular Mechanism of Calcium Waves Using Rapid Scanning Confocal Microscopy

用快速扫描共聚焦显微镜分析了原代培养大鼠肝细胞内钙波的发生机制。苯肾上腺素、加压素和三磷酸腺苷的激素刺激以及HGF的增殖刺激引起胞浆游离钙浓度([Ca^&lt；2&gt；]i)的反复升高。[Ca^&lt；2&gt；]i的增加起源于细胞膜附近的一个特定的相同来源，并以波的形式在细胞内传播。在每个细胞中，由一种激动剂诱发的Ca^&lt；2&gt；波的起源部位与由其他激动剂诱发的Ca^&lt；2&gt；波的起源部位相同。各细胞内不同激动剂诱导的钙编织峰高度也存在相关性。然而，每个细胞对激动剂的敏感性之间没有相关性，这是在加入激动剂后钙离子升高之前的潜伏期测量的。对细胞内几个小区域的钙瞬变的动力学分析表明：(1)细胞内钙瞬变的空间分布模式不依赖于细胞局部1，4，5-三磷酸肌醇(Ins(1，4，5)P3)的增加及其繁殖，而取决于Ins(1，4，5)P3敏感的钙池的分布；(2)每个细胞对激动剂的敏感性与形成的Ins(1，4，5)P3的浓度高度相关。

The mechanism of calcium waves was analyzed in primary cultured rat hepatocytes using rapid scanning confocal microscopy. Hormonal stimulations by phenylephrine, vasopressin and ATP and a proliferative stimulation by HGF induced repetitive increases of cytosolic free Ca^<2+> concentration ([Ca^<2+>] i). The increases in [Ca^<2+>] i originated from a specific same origin adjacent to the cell membrane and propagated across the cell like waves. In each cell the locus where the Ca^<2+> waves induced by an agonist wre originated was the same as those where the Ca^<2+> waves induced by the other agonists were originated. There was also a correlation in the peak height in the Ca^<2+> weaves induced by different agonists in each cell. However, there was no correlation between sensitivity of each cell to the agonists, which were measured as latent periods prior to Ca^<2+> rises after an addition of the agonists. The kinetic analysis of Ca^<2+> transients in several small regions in the cells suggested the followings : (1) the spatial patterns of Ca^<2+> waves were not depending on the increases of inostiol 1,4,5 triphosphate (Ins (1,4,5) P_3) in the limited parts of the cells and its propagation, but on the distribution of Ins (1,4,5) P_3-sensitive Ca^<2+> pools ; (2) the sensitivity of each cell to agonists was highly depending on the concentration of Ins (1,4,5) P_3 formed.