2001 Fiscal Year Final Research Report Summary
Improvement of intestinal absorption of peptide drugs
| Project/Area Number |
12672161
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
医薬分子機能学
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| Research Institution | Tokyo University of Science |
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Principal Investigator |
HAGA Makoto Tokyo University of Science, Facalty of Pharmaceutical Science,associate Professor, 薬学部, 助教授 (70110666)
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| Co-Investigator(Kenkyū-buntansha) |
HAYASHI Masahiro Tokyo University of Pharmacy and Life Science,School of Pharmacy,Professor, 薬学部, 教授 (20012669)
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| Project Period (FY) |
2000 – 2001
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| Keywords | GLUT5 / transporter / peptide drugs / intestinal absorption / fructosylated peptide / BBMV / BLMV |
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| Research Abstract |
In 2000 fiscal year, GGYR, GGYG and GGGYG were synthesized by the Fmoc method using a peptide synthesizer. It was shown that the purity of these peptides was high enough and that further purification was not necessary. Next, BIMVs were prepared from rat small intestine by a Percoll density gradient centrifugation. Both Na^+-K^+ ATPase activity and alkaline phosphatase activity revealed that the basolateral membrane was well separated. The formation of vesicles was confirmed from the dependence of 3^H-glucose uptake on the osmolariiy of outer solution. The uptake of <125>^I-labeled SAPG-GGYR into BLMVs was then studied. The uptake of SAPG-GGYR into BLMVs was significantly increased by glucosylation and was inhibited by cytochalasin B, phloretin and glucose. From these findings, it was confirmed that the uptake was mediated by the GLUT2-like transporter, which existed on the BLM. On the transport mechanism of glucosylated peptide in BBM, it was shown alternatively that the intestinal absorption of B1-Phe-SAPG-Ins was enhanced by its specific adsorption to the SGLT1 transporter (reference 1). In 2001 fiscal year, we synthesized SAPF from D-fructose via NPF and APF, and prepared SAPF-GGYR. The transport mechanism of SAPF-GGYR through the BBM was examined using BBMVs. It was shown that the transport of GGYR through the BBM was significantly enhanced by fructosylation and mediated by a GLUTS-like transporter. We could not study, however, the transport mechanism of SAPF-GGYR in the BLM, increase of resistance to the enzymatic degradation by fructosylation, difference between anomers and between amino acid sequences, which were planed in the beginning. Instead, other study, which may be useful for the absorption mechanism using human intestinal cells and organizations was carried out (reference 2, 3).
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Research Products
(6 results)
