Project/Area Number |
15570051
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Morphology/Structure
|
Research Institution | Keio University |
Principal Investigator |
NAGAI Takatoshi Keio University, School of Medicine, Professor, 医学部, 教授 (50130026)
|
Co-Investigator(Kenkyū-buntansha) |
SUZUKI Atsushi Keio University, School of Medicine, Assistant Professor, 医学部, 専任講師 (90216359)
TANAKA Shigeyasu Shizuoka University, Faculty of Science, Professor, 理学部, 教授 (90146233)
|
Project Period (FY) |
2003 – 2005
|
Project Status |
Completed (Fiscal Year 2005)
|
Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2005: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2004: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2003: ¥2,300,000 (Direct Cost: ¥2,300,000)
|
Keywords | frog / skin / water absorption / sodium channel / water channel / sodium transport |
Research Abstract |
To localize the epithelial sodium channel (ENaC) we raised a polyclonal antibody against a peptide in the extracellular loop of the α subunit of Xenopus ENaC (αxENaC) that had been cloned from A6 kidney cell line. In desert toads, Bufo alvarius, the α ENaC was successfully localized in the apical cell membrane of the most superficial cells in the granulosum cell layer. Next, we used an antibody against, the C-terminal peptide of a water channel protein (aquaporin-2 : AQP-h2) that had been cloned from the ventral skin of the tree frog, Hyla japonica. The antibody recognized a 30.0 kD-protein and immunostained predominantly in the abdominal pelvic skin of B.alvarius. No immunoreactivity was seen in the other area of the skin such as the pectoral and dorsal skins, which is consistent to a water absorption behavior of the desert toads that utilize the pelvic skin. The immunoreactivity was intense in the upper layer of the stratum granulosum and was localized to the apical cell membrane of the principal cells. Exposure of the ventral skin to anti-diuretic hormone (AVT, 10^<-8>M) facilitated more intense immunoreactivity in the apical membrane. Results explain that the desert toad can detect sodium ions in the substrate of water absorption.
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