| Project/Area Number |
11670673
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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 |
Circulatory organs internal medicine
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| Research Institution | Nagoya University |
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Principal Investigator |
YASUI Kenji Nagoya Univ.Res.Inst.of Environ.Med., Assistant Professor, 環境医学研究所, 助手 (70283471)
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| Co-Investigator(Kenkyū-buntansha) |
LEE Jong-kook Nagoya Univ.Res.Inst.of Environ.Med., Assistant Professor, 環境医学研究所, 助手 (60303608)
KAMIYA Kaichiro Nagoya Univ.Res.Inst.of Environ.Med., Associate Professor, 環境医学研究所, 助教授 (50194973)
KODAMA Itsuo Nagoya Univ.Res.Inst.of Environ.Med., Professor, 環境医学研究所, 教授 (30124720)
YAMAZAKI Kiyoko Seinangakuin Univ.Dept.of Literature, Professor, 文学部, 教授
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2000: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1999: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | development / Heart / mouse / If / Calcium / EC-coupling / mRNA / Development |
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| Research Abstract |
1)Developmental change of hyperpolarization-activated inward current(I_fChanneI)
In this study we performed the experiments using embryonic mouse ventricle. We analyzed the expression of HCN gene(HCN 1-4)cording for the hyperpolarization-activated inward current(I_f channel)by the real-time PCR assay. HCN gene was well expressed in 9.5 dpc, but at 18 dpc its expression decreased. The major HCN subtypes detected at 9.5 dpc were HCN4 and HCN1(HCN4 > HCN1). The HCN genes detected at 18 dpc were mainly HCN2, and the switching of HCN gene subtype was observed during the developnvenl. We considered that abnormal automaticity in pathological heart might be due to the hyperpolarization-activated inward current(I_f Channel), and the analysis of the pathological heart is necessary to reveal this possibilily.
2)Developmental Change of Ca^<2+> handling protein
The gene expression of ryanodine receptor(RyR2), sarcoplasmic reticulum Ca^<2+> pump(SERCA2), phospholamban(PLB)and Na^+/Ca^<2+> exchanger were analyzed by the real-time PCR assay. During late embryonic stage(18 dpc), the mRNAs for RyR2, SERCA2 and PLB increased by 8-, 3- and 15-fold(vs 9.5 dpc)respectively, although the NCX1 mRNA was unchanged. After birth, there was a furthur increase in the mRNAs for RyR2(21-fold vs 9.5 dpc), SERCA2(18-fold)and PLB(33-fold), but a 50 % decrease in NCX1 mRNA.We also recorded Ca^<2+> transient using Ca^<2+>-sensitive fluorescent dye. SR inhibitor unaffected Ca^<2+> transient at 9.5 dpc and diminished that at 18 dpc. Ca^<2+> channel blocker eliminated Ca^<2+> transient at 9.5 dpc.
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