| Project/Area Number |
09470005
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General anatomy (including Histology/Embryology)
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| Research Institution | Kansai Medical University |
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Principal Investigator |
KANAMURA Shinsuke Kansai Medical University, Department of Anatomy, Professor, 医学部, 教授 (50027091)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAMORI Yasuharu Kansai Medical University, Department of Anatomy, Instructor, 医学部, 助手 (50309233)
NIHIRA Mika Kansai Medical University, Department of Anatomy, Instructor, 医学部, 助手 (20274194)
WATANABE Jun Kansai Medical University, Department of Anatomy, Associate Professor, 医学部, 助教授 (40148557)
MONDO Hiroko Kansai Medical University, Department of Anatomy, Instructor, 医学部, 助手 (30309249)
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| Project Period (FY) |
1997 – 1999
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| Keywords | CYP2B1 / 2 / acyltransferase / endoplasmic reticulum / phenobarbital / mRNA / in situ hybridization / luminessence / CYP1A1 / 2 |
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| Research Abstract |
In the present study, we analyzed regulatory mechanism for endoplasmic reticulum proliferation through DNA-binding factors by a combination of morphological methods, such as highly sensitive cytochemical methods and stereological analyses, with molecular biological techniques in rat hepatocytes.
(1) Proliferation of the endoplasmic reticulum (ER) membrane in hepatocytes is independent of the induction of membrane-bound proteins. However, a drug, phenobarbital (PB), acts as a trigger for both proliferation of ER and induction of PB-inducible membrane-bound proteins, CYP2B1/2.
(2) Proliferation of ER by PB administration is not caused by suppression of membrane degradation but caused by promotion of biosynthesis of the ER membrane. PB induces glycerophosphate acyltransferase (GAT), a key enzyme for biomembrane synthesis.
(3) Interaction of PB reguratory element (PBRE) with proximal promoter in CYP2B1/2 genes is necessary to activate CYP2B1/2 gene transcription.
(4) We have developed a) in situ Southwestern hybridization technique, b) quantitative immunohistochemical methods to measure each CYP content in hepatocyte cytoplasm and c) a highly sensitive detection method with chemiluminessence and photon counting. By using these techniques, we have also revealed the regulatory mechanism for transcription activation of CYP1A1/2 genes through a DNA-binding factor (heterodimer of AhR and Arnt) in rat hepatocytes.
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