| Project/Area Number |
10557211
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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 |
Physical pharmacy
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| Research Institution | Graduate school of Pharmaceutical sciences, The University of Tokyo |
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Principal Investigator |
SUAUKI Hiroshi Graduate School of Pharm. Sci. The Univ. of Tokyo, Assistant Professor, 大学院・薬学系研究科, 助教授 (80206523)
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| Co-Investigator(Kenkyū-buntansha) |
MOMOSE Toshimitsu Graduate School of Medicine The Univ. of Tokyo, Research Associate, 医学部・附属病院・放射線科, 助手 (20219992)
ISHIKAWA Toshihisa Pfizer Central Research Lab. Principal researcher, 主任研究員
KATO Yukiko Graduate School of Pharm. Sci. The Univ. of Tokyo, Research Associate, 大学院・薬学系研究科, 助手 (30251440)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥12,200,000 (Direct Cost: ¥12,200,000)
Fiscal Year 1999: ¥4,500,000 (Direct Cost: ¥4,500,000)
Fiscal Year 1998: ¥7,700,000 (Direct Cost: ¥7,700,000)
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| Keywords | blood-brain barrier / blood-cerebrospinal fluid barrier / MRP / ABC transporter / Organic anions / 脳毛細血管内皮細胞 / MRP1 / MRP5 / P-糖蛋白 / GS-Xポンプ |
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| Research Abstract |
It has been established that MDR1 P-glycoprotein is expressed on the luminal membrane of the cerebral endothelial cells to restrict the brain entry of its substrates. Recently, it has been suggested that transporters other than MDR1 P-glycoprotein is expressed on the blood-brain barrier to restrict the brain entry of organic anions. In the present study, we have characterized the transport for organic anions across the blood-brain barrier and blood-cerebrospinal fluid (CSF) barrier. As an in vitro model to study the transport across the blood-brain barrier, we have used mouse brain endothelial cells derived cell line (MBEC4). After preloading MBEC4 monolayer with monochlorobimane, we have examined the efflux of intracellularly formed glutathione bimane into the luminal and abluminal sides. We found a high affinity efflux system for this glutathione-conjugate on the luminal membrane. Moreover, it was demonstrated that glutathione bimane is transported in an ATP-dependent manner in membrane vesicles from MBEC4 cells. Western blot analysis indicated the presence of MRP1 both in MBEC4 cells and cerebral endothelial cells freshly isolated from rat brain. In the same manner, we examined the role of MRP in the blood-cerebrospinal fluid (CSF) barrier. After intracerebroventricular administration, 17b estradiol 17b-D-glucuronide, an MRP family substrate, was rapidly eliminated from the CSF across the blood-CSF barrier. Moreover, we found that the expression level of MRP1 in the choroid plexus is 4-5 times higher than that in the lung, one of the tissues extensively expressing MRP1. These results indicate that MRP family proteins are expressed on the blood-brain barrier and blood-CSF barrier to restrict the brain entry of organic anions. By regulating the function of efflux transporters, it may be possible to improve the brain entry of their substrates.
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