| Project/Area Number |
09556026
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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 | 展開研究 |
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| Research Field |
食品科学・栄養科学
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| Research Institution | The University of Tokyo |
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Principal Investigator |
SHIMIZU Makoto The University of Tokyo, Graduate School of Agricultural and Life Sciences, Professor, 大学院・農学生命科学研究科, 教授 (30114507)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Hirohito The University of Tokyo, Graduate School of Agricultural and Life Sciences, Rese, 大学院・農学生命科学研究科, 助手 (20270895)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥7,800,000 (Direct Cost: ¥7,800,000)
Fiscal Year 1998: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1997: ¥5,300,000 (Direct Cost: ¥5,300,000)
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| Keywords | intestinal epithelial cell / detection method for toxicants / transepithelial electrical resistance / monolayer culture / tight junction / 毒性試験 / 腸管細胞 |
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| Research Abstract |
Development of a novel experimental method for the detection of toxicants in food was attempted by using a monolayer culture system with intestinal cpithelial cells. A variety of toxicants seemed to be detectable by measuring transepithelial electrical resistance (TER) of the human intestinal Caco-2 cell monolayer after exposure to the toxicants. By adding such toxicants as benzalkonium chloride(a membrane perturbing toxicant with surface activity), flammutoxin and discodermin A (membrane pore-forming toxicants), mycalolide B and cytochalasin D (actin filament-disturbing toxicants), caliculin A and okadaic acid(protein phosphatase inhibitory toxicants)to the apical chamber of the Caco-2 cell monolayer, rapid decrease in TER was observed. Sodium azide, a metabolic inhibitor, also decreased the TER in a time-dependent manner. Although the mechanisms for the cell damage caused by the above-mentioned toxicants are different each other, the disruption or disturbance of the cytoskeletal stru
… More
cture may occur as a common change. The changes in the cytoskeletal structure may induce the reorganization of tight junctional molecules, resulting in the increase of the tight junctional permeability. The TER decrease commonly observed as a response to cytotoxic substances is thought to reflect the changes in cytockeletal/tight junctional structure. On the other hand, such bacteria toxins as verotoxin 1&2 and a marine toxin, onnamide A(protein biosynthesis inhibitory toxicants)did not affect the TER of the Caco-2 monolayer. The present detection method seems to be not applicable for the toxins which take longer time to express their toxicity. The decrease in TER of the cell monolayer was accompanied with the increase in the permability for proteins. This system is therefore thought to be useful not only for the detection of substances with cytotoxicity but also for the detection of harmful substances which disrupt the intestinal barrier and enhance the absorption of food allergens and xenobiotics. Less
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