1988 Fiscal Year Final Research Report Summary
Studies on the gonadotropin release by pulsatile and continuous GnRH stimulations
| Project/Area Number |
61570801
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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 |
Obstetrics and gynecology
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| Research Institution | Yokohama City University School of Medicine |
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Principal Investigator |
UEMURA Tsuguo Yokohama City University School of Medicine, 医学部, 助教授 (40046040)
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| Co-Investigator(Kenkyū-buntansha) |
KIMURA Akihiro Yokohama City University School of Medicine, 医学部, 助手 (40192017)
MINAGUCHI Hiroshi Yokohama City University School of Medicine, 医学部, 教授 (20010176)
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| Project Period (FY) |
1986 – 1988
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| Keywords | GnRHanalog / pituitary / desensitization / receptor |
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| Research Abstract |
In this study, (1)the mechanism of gonadotropin release from the pituitary (2)desensitization of the pituitary by GnRHanalog(GnRHa) (3)direct effects of GnRHa on the ovary and (4)clinical applications of GnRHa were investigated.
The results were as follows; (1)the mechanism on signal transmission of GnRHa is performed by C-kinase system as well as A-kinase system and by arachidonic acid, especially products of lipoxygenase path way. (2)in vivo administration of GnRHa decreased numbers of GnRH receptors and diminished the responses of gonadotropin to GnRH. On of the pituitary cells attached with beads a continuous infusion of GnRH 10@>D1-8@>D1M(0.13ml/min) induced desensitization to GnRH, but K^+, cAMP and GnRH(10^<-6>M) stimulated gonadotropin release even from the desensitized pituitary. These results showed that the storage of gonadotropin in the pituitary was preserved well and that the desensitization was mainly dueto the disturbance in the receptor level. (3)In the hypophysectomized immature female rats a administration of GnRHa inhibited the ovarian weight and the binding sites of HCG in the PMSG-treated ovary. GnRHa promoted 20alpha HSD activity and inhibited aromatase activity in the granulosa cell. C-kinase system seems to participate in the signal transmission of GnRH in the ovary, too(4). GnRHa (900mu g/day in) induced 50% reduction of volumes ofthe uterus with myoma.
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Research Products
(20 results)
