| Project/Area Number |
13307063
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical pharmacy
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| Research Institution | TOYAMA MEDICAL AND PHARMACEUTICAL UNIVERSITY |
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Principal Investigator |
TAKEGUCHI Noriaki Toyama Medical and Pharmaceutical University, Vice president, 副学長 (00019126)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAI Hideki Toyama Medical and Pharmaceutical University, Faculty of Pharmaceutical Sciences, Associate Professor, 薬学部, 助教授 (60242509)
ASANO Shinji Toyama Medical and Pharmaceutical University, Life Science Research Center, Associate Professor, 生命科学実験センター, 助教授 (90167891)
HATANAKA Yasumaru Toyama Medical and Pharmaceutical University, Faculty of Pharmaceutical Sciences, Professor, 薬学部, 教授 (30111181)
MORII Magotoshi Toyama Medical and Pharmaceutical University, Faculty of Pharmaceutical Sciences, Lecturer, 薬学部, 講師 (60019130)
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| Project Period (FY) |
2001 – 2003
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| Keywords | gastric proton pump / gastric acid secretion / gastric flippase / proton pump inhibitor / chloride channel / cytoprotection / interleukin / nitric oxide |
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| Research Abstract |
1.We succeeded to construct a stable cell line(polarized LLC-PK1 cell) expressing the gastric proton pump α-and β-subunits. By using this cell line, we found for the first time that the gastric proton pump functions as phospholipid flippase.
2.In the studies using HEK-293 cells expressing gastric proton pump, we found that the amino acid residues important for the proton pump function in the M6 segment are exclusively localized on the one side of the putative α-helical structure. We also found that all three disulfide bonds in the ectodomain of the β-subunit are necessary for the α-β assembly, proton pump activity, stability of the α-and β-subunits, and cell surface delivery of the α-subunit.
3.We succeeded to establish conditionally immortalized gastric mucosal cell lines expressing mRNA for gastric proton pump from transgenic mice harboring temperature-sensitive simian virus 40 large T-antigen.
4.We found that IL-1β binds to the IL-1 receptor of rabbit gastric parietal cells and inhibits the basolateral housekeeping Cl^-channel via G protein-mediated Rho/Rho-kinase-dependent production of O_2^-. CLCA1 is not a subunit of the gastric housekeeping Cl^-channel.
5.We found that the NO-dependent novel mechanism of activation of Cl^-channels in rat colonic mucosa. In this mechanism, NO stimulates the production of thromboxane A_2, and the released thromboxane A_2 activates the Cl^-channels in colonic crypt cells.
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