1988 Fiscal Year Final Research Report Summary
Neuroendocrine Regulation on Age-related Changes of Reproductive Function
| Project/Area Number |
62480023
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
動物形態・分類学
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| Research Institution | University of Tokyo (1988)
Hiroshima University (1987) |
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Principal Investigator |
KAWASHIMA Seiichiro Faculty of Science, Hiroshima University (until 1988 Sept) Faculty of science, University of Tokyo (from 1988 Oct), 理学部, 教授 (20011554)
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| Co-Investigator(Kenkyū-buntansha) |
MORI Takao Faculty of Science, University of Tokyo. (from 1988 Oct), 理学部, 講師 (80011659)
TSUTSUI Kazuyoshi Faculty of Science, Hiroshima University (until 1988 Sept), 理学部, 助手 (20163842)
TAKAHASHI Sumio Faculty of Science, Hiroshima University, 理学部, 助手 (90144807)
MACHIDA Takeo Faculty of Science, Hiroshima University (until 1988 Sept), 理学部, 助教授 (70073020)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Reproductive function / aging / central nervous system / LHRH / FSH receptor / prolactin / growth hormone / ニューロンの可塑性 |
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| Research Abstract |
The purpose of the present study is to analyze the mechanism of age-relate changes of reproductive function, with special reference to neuroendocrine function. The important findings are summarized as follows.
1. The results of immonocytochemistry and radioimmonoassay revealed that LHRH neurons start functioning earlier in male rats than females. For the maintenance of cyclic release of LHRH and LH in adult female rats, the suprachiasmatic nucleus could normally play a role, if either the anterior or posterior afferents was left intact.
2. As concerns the pulsatile release of growth hormone (GH), old rats showed a decrease in pulse peak and pituitary content of GH. Simultaneously, the increase in the number of GH binding sites in hepatic membrane fraction and the decrease in plasma level of somatomedin-C were found.
3. Age-related changes in the hypothalamic-neurohypophyseal system was also studied. It was found that vasopressin neuronal plasticity was decreased as age advances. This finding affords an approach to age-related changes in other neuroendocrine system.
4. Follicle-stimulating hormone (FSH) receptor in the testes was low in affinity at first but before parturition the affinity increased to the adult level. In the mouse, the concentration of testicular FSH receptors increased until puberty similar to that in the rat. However, in the mouse fsh receptors decreased after puberty due to downregulation of FSH receptors. The electron microscopic autoradiography and kinetic study revealed that internalization of FSH-FSH receptor complex is important for the downregulation.
Representative reports for the present project are listed in the next page.
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