Mechanism underlying the spontaneous changes in the cytosolic CaィイD12+ィエD1concentrations in rat adrenal chromaffin cells
| Project/Area Number |
10670045
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General physiology
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| Research Institution | Kagoshima University |
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Principal Investigator |
SORIMACHI Masaru Kagoshima University, Faculty of Medicine, Professor, 医学部, 教授 (70036440)
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| Co-Investigator(Kenkyū-buntansha) |
KAMEYAMA Masaki Kagoshima University, Faculty of Medicine, Professor, 医学部, 教授 (60150059)
YAMAGAMI Kazuhiko Kagoshima University, Faculty of Medicine, Research Associate, 医学部, 助手 (30041354)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1999: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1998: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Mouse adrenal medulla / the cytosolic CaィイD12+ィエD1concentration / confocal microscope / Oregon-green-BAPTA-1 / ATP / gap-junction / lucifer yellow / Rhodamine green dextran / ロダミン-グリーン-デキストラン / 共焦点レーザ顕微鏡 / ネズミ副腎髄質 / オレゴングリーンBAPTA-1 |
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| Research Abstract |
The spontaneous fluctuations of the cytosolic CaィイD12+ィエD1 concentrations ([Ca]ィイD2inィエD2) have often been observed in isolated single rat adrenal chromaffin cells. To see whether these [Ca]ィイD2inィエD2 changes occur also in vivo, we measured [Ca]ィイD2inィエD2 in individual chromaffin cells involved in adrenal slice preparations after loading with Oregon-green-BAPTA-1/AM. We often observed the spontaneous changes in [Ca]ィイD2inィエD2 when measured with cofocal laser-scanning microscope. In addition, we found that the spontaneous [Ca]ィイD2inィエD2 increase immediately spreads to the neighboring cells in some cases. The synchronization of [Ca]ィイD2inィエD2 increases among the neighboring cells occurs more frequently in mouse adrenal medullary slice preparations, where the gap-junction has been shown to exist. Treatment of mouse adrenal slices with the ATP receptor antagonist PPADS did not inhibit the spread of CaィイD12+ィエD1 signals, and ATP increased [Ca]ィイD2inィエD2 in only 30% of isolated cells tested, suggesting that ATP released from the cells is not responsible for the excitation of the neighboring cells. We also investigated the effects of the inhibitors of gap-junctions on the spread of CaィイD12+ィエD1 signals, but these agents markedly inhibited the occurrence of the spontaneous [Ca]ィイD2inィエD2 increase. However, the combined loading of Lucifer yellow and Rhodamine green dextran-70000 into the cells through the damaged membrane revealed that the distribution pattern of the former agent, which passes through the gap-junctions, was broader than that of the latter. These results suggest that the synchronized [Ca]ィイD2inィエD2 changes among cells were mediated by the gap junctions between the cells.
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Report
(3 results)
Research Products
(5 results)
