1995 Fiscal Year Final Research Report Summary
Functional expression, intracellular translocation, structure-function relationship of water channels in the collecting duct.
| Project/Area Number |
06671134
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Kidney internal medicine
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| Research Institution | Tokyo Medical and Dental University |
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Principal Investigator |
KUWAHARA Michio Tokyo Medical and Dental University, School of Medicine, Lecturer, 医学部, 講師 (60221230)
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| Co-Investigator(Kenkyū-buntansha) |
SASAKI Sei Tokyo Medical and Dental University, School of Medicine, Associate Professor, 医学部, 助教授 (60170677)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Collecting duct / Water channel / Protein kinase A / H-K-ATPase |
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| Research Abstract |
1.We cloned a water channel in the basolateral membrane of the rat kidney collecting duct (AQP3). AQP3 was permeable to glycerol and urea in addition to water.
2.We determined functional characteristics and localization of a vasopression-sensitive water channel in the apical membrane of the kidney collecting duct (AQP2). AQP2 was not permeable to urea, and inhibited by mercury. AQP2 was localized sub-apical membrane area of the principal cells.
3.We examined the mechanisms of regulatory volume decrease in rabbit kidney collecting duct. Basolateral K^+ channel and Cl^- channel were mainly responsible for the cell volume regulation.
4.The regulatory mechanisms of AQP2 was examined.cAMP increased the water permeability of AQP2 cRNA-injected oocytes and phosphorylated AQP2 at Serine 256, indicating that AQP2 is regulated by protein kinase A.
5.We examined functional activity of H-K-ATPase in the rabbit collecting duct. The activity of H-K-ATPase was confined to the apical membrane of intercalated cells and inner stripe cells, and was stimulated by K^+ depletion.
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