| Project/Area Number |
18590199
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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 | Hokkaido University |
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Principal Investigator |
ISHIKAWA Toru Hokkaido University, Graduate School of Veterinary Medicine, Associate Professor (70249960)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥300,000)
Fiscal Year 2007: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2006: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | Bovine parotid / Bicarbonate secretion / Cation channel / 陽イオンチャネル |
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| Research Abstract |
Ruminant parotid glands secrete continuously large volumes of HCO_3-rich saliva even at resting, but the underlying molecular mechanism remains unclear. Since ruminant parotid secretory cells contain several ion channels that can be regulated by intracellular Ca^<2+> and Mg^<2+>, resting cellular homeostasis of these divalent cations might also play an important role in the continuous HCO_3 secretion. Towards better understanding the mechanism of the parotid HCO_3 secretion, this project focused on TRPM6 and TRPM7 that are known to be cation channels permeable to divalent cations such as Ca^<2+> and Mg^<2+>. Using electrophysiological and molecular biological techniques, it was found that 1) bovine parotid acinar cells exhibit a membrane current, which is sensitive to intracellular Mg^<2+> as reported for recombinant TRPM7 and TRPM6 currents, 2) bovine parotid cells express transcripts of TRPM6 and TRPM7, 3) TRPM7 that was cloned from bovine parotid was functional in a heterologous expression system. These basic results would be useful for future studies to address the issues as to not only the molecular basis and cellular regulation of the native TRPM6/7-like conductance in bovine parotid acinar cells, but also the role of TRPM6 and TRPM7 in epithelial HCO_3 secretion.
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