1995 Fiscal Year Final Research Report Summary
ROLE OF PINEAL HORMONE IN THE REGULATORY MECHANISM FOR EGG-LAYING OF POULTRY
| Project/Area Number |
06660362
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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 |
Applied animal science
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| Research Institution | TOKYO UNIVERSITY OF AGRICULTURE |
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Principal Investigator |
TANAKA Katsuhide TOKYO UNIVERSITY OF AGRICULTURE, Faculty of Agriculture, PROF., 農学部, 教授 (20021678)
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| Co-Investigator(Kenkyū-buntansha) |
KAWASHIMA Mitsuo GIFU UNIV., ANIM.PROD.SCI., PROF., 農学部, 教授 (10177686)
KUWAYAMA Takehito TOKYO UNIVERSITY OF AGRICULTURE, Faculty of Agriculture, LECTURER, 農学部, 講師 (40215124)
MONJI Yasunori TOKYO UNIVERSITY OF AGRICULTURE, Faculty of Agriculture, ASSOC.PROF., 農学部, 助教授 (50096682)
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| Project Period (FY) |
1994 – 1995
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| Keywords | chicken / pineal hormone / melatonin receptor / rediologand assay / ovulatory cycle / hypothalamus / anterior pituitary / granulosa cell |
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| Research Abstract |
Plasma membrane fractions of tissues of the hypothalamic preoptic area and median eminence area, the anterior lobe of pituitary, and the ovarian follicular granulosa and threca cells were analyzed by radioligand assays for binding properties to tritium labeled metatonin, the pineal hormone. The membrane fractions of all of the tissues except for those of the ovarian follicular theca cells revealed the binding specificity for melatonin among melatonin-related substances and the saturable binding to ^3H-melatonin. By Scatchard analyzes of the specific binding to ^3H-melatonin, the binding component was found to have a single class of binding sites, a high affinity and a limited capacity, indicating that the binding component can be regarded as being a receptor for melatonin. The binding affinity and capacity in the hypothalamic preptic area and median eminence area changed during an ovulatory cycle in laying hens and during a 24h period in nonlaying hens, but the pattern of the change was not different between the laying and nonlaying hens but different between the two hypothalamic areas. The specific binding to ^3H-melatonin in the anterior lobe of pituitary changed during the ovulatory cycle in laying hens, but did not change during a 24-h period in nonlaying hens, suggesting that the binding of melatonin receptor in the pituitary may be related to the egg-laying. The results of the present study suggest a direct action of melatonin on the hypothalamus, the pituitary, and the ovarian follicular granulose cells in the hen.
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