Minamikawa T, Takahashi A, Fujita S
Department of Pathology, Kyoto Prefectural University of Medicine, Japan.
Cell Calcium. 1995 Mar;17(3):167-76. doi: 10.1016/0143-4160(95)90031-4.
We analyzed spatio-temporal characteristics of Ca2+ transients in the cytosol and the nucleus of cultured neonatal rat heart cells using confocal imaging with Indo-1 and Fluo-3. In resting heart muscle cells, nuclear [Ca2+] was maintained lower than the cytosolic level. The rise in nuclear [Ca2+], during either E-C coupling or propagation of the Ca2+ wave, began at the edge of the nucleus in the immediate vicinity of the rise in global or localized cytosolic [Ca2+], and spread inwardly. The rise in [Ca2+] was slower and smaller in the nucleus than in the cytosol. The decay in [Ca2+] was also slower in the nucleus than the cytosol, thereby reversing the initial [Ca2+] gradient between them. Caffeine markedly enhanced the rise in nuclear [Ca2+] while maintaining inward spreading. The heterogeneity of nuclear Ca2+ transients during cellular contractilities suggests that influx of Ca2+ from perinuclear stores into the nucleus plays a predominant role in the nuclear [Ca2+] rise. The results also indicated that spatio-temporal characteristics of Ca2+ transients are quite different between the nucleus and the cytosol, thereby suggesting that they are differentially regulated in the nucleus and the cytosol.
我们使用 Indo-1 和 Fluo-3 共聚焦成像技术分析了培养的新生大鼠心脏细胞胞质溶胶和细胞核中 Ca2+ 瞬变的时空特征。在静息心肌细胞中，细胞核内的 [Ca2+] 维持在低于胞质溶胶水平。在 E-C 偶联或 Ca2+ 波传播过程中，细胞核内 [Ca2+] 的升高始于细胞核边缘，紧邻整体或局部胞质溶胶 [Ca2+] 的升高，并向内扩散。细胞核内 [Ca2+] 的升高比胞质溶胶中的更缓慢、幅度更小。细胞核内 [Ca2+] 的衰减也比胞质溶胶中的更慢，从而逆转了它们之间最初的 [Ca2+] 梯度。咖啡因显著增强了细胞核内 [Ca2+] 的升高，同时保持向内扩散。细胞收缩过程中细胞核 Ca2+ 瞬变的异质性表明，Ca2+ 从核周储存库流入细胞核在细胞核内 [Ca2+] 的升高中起主要作用。结果还表明，细胞核和胞质溶胶中 Ca2+ 瞬变的时空特征有很大差异，从而表明它们在细胞核和胞质溶胶中受到不同的调节。
