Ca<sup>2+</sup> Localization in Thapsigargin-Treated MEG-01 Cells
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- Yabusaki Katsumi
- Biosignal Engineering Division, Kowa Research Institute, Kowa Co., Ltd.
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- Shirasawa Yoshiaki
- Biosignal Engineering Division, Kowa Research Institute, Kowa Co., Ltd.
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- Ozaki Yukio
- Department of Clinical and Laboratory Medicine, Yamanashi Medical College
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- Kume Shoji
- Department of Clinical and Laboratory Medicine, Yamanashi Medical College
説明
To study the intracellular Ca2+ mobilization of MEG-01 cells, which are a megakaryoblastic leukemia cell line, we used thapsigargin, a specific inhibitor of intracellular Ca2+-pump. The stimulation of single, fura-2-loaded MEG-01 cells by thapsigargin resulted in a rise in intracellular Ca2+ concentration ([Ca2+]i) that appears to be due to both initial discharge of Ca2+ from the intracellular stores and successive entry of Ca2+ across the plasma membrane. After removal of extracellular Ca2+, the elevated [Ca2+]i produced by thapsigargin decreased with an initial rapid phase, followed by a gradual phase. lonomycin applied during the period of the gradual decrease elicited a transient increase in [Ca2+]i while La3+, which blocks both inward and outward movement of Ca2+ across the plasma membrane, produced a sustained elevation as long as La3+ was present. Using a laser scanning confocal fluorescence imaging system, localization of cytosol Ca2+ was found in fluo-3-loaded cells in the gradual decrease phase. Heterogeneous pattern of cytosol high Ca2+ concentration seemed to correspond to location of mitochondria labeled with rhodamine 123. Inhibitors of mitochondrial electron transport, NaN3 and antimycin A, eliminated the gradual decrease phase. These results suggest the presence of an unknown intracellular Ca2+ pool, possibly mitochondria, which could accumulate excessive intracellular Ca2+, and indicate that the [Ca2+]i in the gradual decrease phase represents the Ca2+ concentration in the unknown pool.
収録刊行物
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- bioimages
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bioimages 4 (3), 99-109, 1999
日本バイオイメージング学会
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詳細情報 詳細情報について
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- CRID
- 1390007846293860096
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- NII論文ID
- 130008086331
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- ISSN
- 09192719
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- 本文言語コード
- en
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- データソース種別
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- JaLC
- CiNii Articles
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- 抄録ライセンスフラグ
- 使用不可
