1993 Fiscal Year Final Research Report Summary
Involvement of thuroid gland on the seasonal breeding of Japanese monkeys
Project/Area Number |
04640688
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
動物形態・分類学
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Research Institution | KYOTO UNIVERSITY |
Principal Investigator |
NOZAKI Masumi Primate Res.Inst.Kyoto Univ.Assistant professor, 霊長類研究所, 助手 (70136232)
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Co-Investigator(Kenkyū-buntansha) |
SHIMIZU Keiko Primate Res.Inst.Kyoto Univ.Technicians, 霊長類研究所, 教務職員 (90135616)
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Project Period (FY) |
1992 – 1993
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Keywords | Japanese monkeys / Seasonal breeding / Menstrual cycle / Thyroid gland / Thyroxine / Primates / Photoreflactoriness |
Research Abstract |
To examine the role of thyroid hormones on the seasonal breeding of Japanese monkeys (Macaca fuscata), sexually mature females were thyroidectomized (n=6) in early December, during the mid-breeding season, or they remained thyroid intact (n=4). They were housed indoors individually, and blood samples were collected three times a week to monitor gonadotropin and gonadal hormone secretions. All animals ovulated during the breeding season before operation. Thyroidectomy resulted in earlier termination of the breeding season in all animals : ovulatory cycles of thyroidectomized animals were terminated soon after thyroidectomy. Thyroidectomized animals exhibited significantly higher levels of plasma prolactin than those of controls. These results suggest that thyroid hormones are involved in the regulation of the seasonal breeding of Japanese monkeys at least by mediating the modification of prolactin secretion.
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