| Project/Area Number |
17580276
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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 |
Clinical veterinary science
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| Research Institution | Obihiro University of Agriculture and Veterinary Medicine |
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Principal Investigator |
MATSUI Motozumi Obihiro University of Agriculture and Veterinary Medicine, Faculty of Animal Husbandry, Assistant Professor (20374762)
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| Co-Investigator(Kenkyū-buntansha) |
MIYAKE Yoh-Ichi Obihiro University of Agriculture and Veterinary Medicine, Faculty of Animal Husbandry, Professor (20002256)
MIYAMOTO Akio Obihiro University of Agriculture and Veterinary Medicine, Graduate School of Animal and Food Hygiene, Professor (10192767)
KAWASHIMA Chiho Obihiro University of Agriculture and Veterinary Medicine, Faculty of Animal Husbandry, Assistant Professor (20374770)
金子 悦史 帯広畜産大学, 大学院畜産学研究科, COE研究員 (90374769)
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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 |
¥3,710,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥210,000)
Fiscal Year 2007: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2006: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2005: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | Follicular cyst / Follicular development / Pathophysiology / Ovulation failure / Corpus luteum / 臨床獣医学 / 病態生理学 |
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| Research Abstract |
This series of study focused on pathophysiology of follicular cyst in dairy cow. We examined follicular development during cyst formation using corpus luteum (CL)-absence model. The major output from this study is as follows;
1. In CL-absence model, pulsatile secretion of LH from pituitary was increased, and two dominant follicles were selected during follicular development, and then ovulated. These results indicated that follicular development was stimulated under the CL-absence condition in dairy cow.
2. The effects of extension of a period of CL-absence condition on follicular development were examined. Induction of follicular cyst was observed in half of cows after extension of CL-absence condition by repeat of follicle aspiration. Results from hormonal analysis indicated that lack of exposure of progesterone cause low responsiveness of hypothalamus to estrogen. Exogenous progesterone treatment, such as CIDR or PRID, could reinitiate the positive feed back system of hypothalamus to estrogen.
3. To analyze intrafollicular environment during cyst formation, we collected follicular fluid from developing follicle under CL-absence condition. High levels of estrogen and IGF-I were observed in follicular fluid. This result indicates that intrafollicle environment of developing follicle to cyst might stimulate follicular growth by enhanced LH pulse under low progesterone condition.
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