| Project/Area Number |
61570032
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
神経解剖学
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| Research Institution | Showa University |
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Principal Investigator |
NAITO Nobuko Showa University School of Medicine; Lecturer, 医学部, 講師 (30053903)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1987: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1986: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Melanin-concentrating hormone (MCH) / <alpha>-MSH / Rat / Hypothalamus / Neuropeptide coexistence / Immunohistochemistry / Radioimmunoassay / バイオアッセイ / 神経ペプチド / 免疫組職化学 |
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| Research Abstract |
Melanin-concentrating hormone (MCH) is a neuropeptide synthesized in the teleost hypothalamus and stimulates melanin aggregation within teleost melanophores. In the rat brain, however, MCH-bioactivity and immunoreactivity have been reported independently.
In the present project, we characterized MCH-like substance in the rat brain by both an in vitro fish-scale melanophore-bioassay and a radioimmunoassay (RIA) with an antiserum against salmon MCH. Futhermore, subcellular localization of the MCH in the rat brain was examined by immunocytochemistry using electron microscopy. 1. Structure-activity relationships of the salmon MCH molecule were confirmed. MCH-bioactivity requires the disulfide bonding between cystein and amino acid residues (Tyr^<11> and Arg^<12>). Salmon MCH antiserum used in our studies is directed towards the carboxy-terminus and requires the cyclic configuration for recognition. 2. MCH-immunoreactivity and -bioactivity were present together in the same effluent fractions of the rat hypothalamic extract by reverse-phase high-performance liquid chromatography (HPLC). 3. MCH-immunoreactive cell bodies in the rat brain were confined to the hypothalamus. At electron microscopic level, MCH-immunoreactivity was located specifically in secretory granules in MCH-positive neurons and their processes. 4. Coexistence of immunoreactivity for MCH and -MSH was presented in the hypothalamus of the rat.
Our results strongly upport the notion that rat MCH-like substance may be homologous but not identical to salmon MCH, and may serve some neurotransmitter and/or neuromodulator role in the brain of the rat.
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