| Project/Area Number |
17580264
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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 |
Basic veterinary science/Basic zootechnical science
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| Research Institution | Nagoya University (2007)
National Institute of Agrobiological Sciences (2005-2006) |
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Principal Investigator |
OHKURA Satoshi Nagoya University, Graduate School of Bioagricultural Sciences, Associate Professor (20263163)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,310,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥210,000)
Fiscal Year 2007: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2006: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2005: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | nutrition / gonadotropin / gonadotropin-relFAsing hormon / ketone body / monocarboxylate transporter / Shiba goat / PCR / nucleotide sequence / RT-PCR |
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| Research Abstract |
Reducing of nutrition can lead to infertility and how nutrition controls reproductive functions remains a major unsolved question. Pulsatile gonadotropin-releasing hormone (GnRH) secretion is the central process of reproduction, and understanding its regulation by metabolic signals is essential to clarify the issue how nutrition influence the reproductive activity. The goal of this study is to identify which blood-borne substances are used as signals reflecting the availability of metabolic fuel. Ketone body has been suggested to play a role as a metabolic regulator of GnRH release in monogastric animals, but its role in ruminants has been examined. Transport of ketone body through cell membrane depends on the monocarboxylate transporters (MCT), thus MCT would be a key molecule for ketone body action. In the present study, we identified the nucleotide sequence of MCTI cDNA originated from goat hypothalamus, RT-PCR analysis of distribution of goat MCTI in several tissues, and central injection of ketone body (beta-hydroxybutyrate [bHBA]) on the activity of GnRH. pulse generator in goats. We found the following : 1) A partial cDNA sequence including cording region for goat MCTI (1506 bp) was determined from the hypothalamus. 2) Deduced amino acid sequence of goat MCTI showed high (≧97%) homologies with cattle and sheep MCTI, and putative 12 transmembrane regions. 3) MCT1 was expressed in tissues around the whole body we tested, but the expression levels seemed to be different among tissues. 4) Central administration of bHBA (80 pmol/h for 5 h) suppressed GnRH pulse generator activity in goats. The action site of bHBA would be in the brain, because plasma bHBA concentrations unchanged after central infusion. These findings suggest that central ketone body increased during energy deficiency is sensed with specific sensing mechanism via MCT in the brain and acts as a metabolic signal suppressing GnRH pulse generator activity in goats
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