| Project/Area Number |
01440018
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
General anatomy (including Histology/Embryology)
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| Research Institution | Keio University |
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Principal Investigator |
YASUDA Kenjiro Keio Univ. School of Medicine, Professor, 医学部, 教授 (90050327)
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| Co-Investigator(Kenkyū-buntansha) |
SHIOZAWA Masahide Keio Univ. School of Medicine, Assistant, Professor, 医学部, 講師 (50170840)
YAMASHITA Shuji Keio Junior College of Nursing, Professor, 教授 (90050666)
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| Project Period (FY) |
1989 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥14,500,000 (Direct Cost: ¥14,500,000)
Fiscal Year 1991: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1990: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1989: ¥11,900,000 (Direct Cost: ¥11,900,000)
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| Keywords | -GTP / Northern blot analysis / In situ hybridization / mRNA / in situ hybridization / γGTP / γ-GTP |
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| Research Abstract |
Gamma-glutamyl transpeptidase (gamma-GT) is a membrane-bound enzyme which catalyzes hydrolysis of the gamma glutamyl moiety of amino acids and peptides, and transfers the g-glutamyl residue to the other amino acids and peptides. It is considered to be an oncofetal protein and has been reported to be involved in detoxification in cell membrane transport of amino acids and peptides in liver, ammoniagenesis in kidney, and production of leucotfienes. The aim of the present study was to measure the amount of gamma-GT mRNA and to determine the amount and localization of gamma-GT protein in human liver during fetal development to understand the possible role of gamma-GT in liver development.
Expression of human gamma-GT gene in liver during fetal development was examined using Nonhem analysis and in situ hybridization by gamma-GT cDNA as a probe. The expression was detectable as early as at week 12 of gestation and then increased gradually to a peak at week 40, just before birth. The maximal level of the expression in the fetal liver was ten-fold higher than that in adult liver and comparable to that in a hepatocellular carcinoma.
Production and localization of gamma-GT in liver were determined immunohistochemically using monoclonal antibodies against human gamma-GT. In parallel to the increase in mRNA synthesis, an increase in areas as well as intensity of immunostaining was observed. Furthermore, gamma-Gr protein was shown to be localized restrictively oil the wall of bile canaliculi when the expression was low, but distributed widely over all along the cell membrane of the fetal liepatocytes when the expression was high.
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