Investigation of sympathetic nerve in Parkinson's disease model mice

2007 Fiscal Year Final Research Report Summary

• Project/Area Number: 17591243
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Radiation science
• Research Institution: University of Tsukuba
• Principal Investigator: FUKUMITSU Nobuyoshi University of Tsukuba, Graduate School of Comprehensive Human Sciences, Assistant Professor (40277075)
• Co-Investigator(Kenkyū-buntansha): SUZUKI Masahiko The Jikei University, School of Medicine, Assistant Professor (20266638) ; FUKUDA Takahiro The Jikei University, School of Medicine, Assistant Professor (60228913) ; KIYONO Yasushi Fukui University, Biomedocal imaging research center,, Assistant Professor (50305603)
• Project Period (FY): 2005 – 2007
• Keywords: Parkinson's disease / MIBG / norepinephrine

Research Abstract

MPTP was injected to C57BL6 male mice (15 weeks) and Parkinson's disease model mice was made. Injected dose of MPTP was 40 mg/BW. Mice were divided into 6 groups (control, MPTP administration 1-day, 4-days, 7-days, 21-days and 3-times [7, 14, 21 days] before). In RI experiment, (14 mice in each group) 4 hours after ^<125>I-MIBG injection, mice were sacrificed, and cardiac ^<125>I-MIBG uptake, norephephrine, dopamine, thyrosine concentration were measured. In non-RI experiment (20 mice each), striatum dopamine concentration and cardiac norepinephrine transporter was measured. ^<125>I-MIBG uptake was rapidly reduced in 1-day, followed by gradually recovered in 7-day. And it was reduced after 3-times repeated MPTP administration. Striatum dopamine and cardiac norepinephrine concentration showed similar pattern. However, cardiac dopamine and tyrosine concentration showed no significant change, that means norepinephrine synthesis damage is time-dependent. Binding potential of norepinephrine transporter rapidly reduced in 1-day, however no significant change was found after that. In sympathetic nerve of Parkinson's disease model mice, both of binding potential of norepinephrine transporter and norepinephrine synthesis reduced in early stage at first. However, norepinephrine synthesis recovered gradually after that. And long-term and repeated MPTP administration, still more makes reduction of norepinephrine synthesis.