| Project/Area Number |
60570777
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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 | Kobe University |
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Principal Investigator |
ASHITAKA Yoshihiko Associate Professor, Kobe University School of Medicine, 医学部, 助教授 (10030959)
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| Co-Investigator(Kenkyū-buntansha) |
OHASHI Masanobu Research Associate, Kobe University Hospital, 附属病院, 助手 (90176975)
MARUO Takeshi Assistant Professor, Kobe University Hospital, 附属病院, 講師 (60135811)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1986: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1985: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Thyroid hormone / TSH / 5-deiodinase / Thyroid function / HCG / asialo-hCG / placenta / IUGR |
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| Research Abstract |
1. Thyroid Function during Perinatal Period and 5-deiodinase Activity in Placenta: Thyroid function of pregnant women estimated by measuring the serum concentrations of f- <T_3> , f- <T_4> and r- <T_3> suggested that the metabolic situation of pregnant women would become hypometabolic along the course of pregnancy toward parturition. Placental 5-deiodinase semmed to prevent active movement of thyroid hormones from mother to fetus by deiodinating inner-ring iodine of <T_4> to r- <T_3> . Hyper r- <T_3> and lower <T_3> levels in such pathological women as IUGR and pregnancy induced hypertension indicated that those patients would be the much lower metabolic situations to which placental higher 5-deiodinase activity might be related. Serum level of TSH in the neonate incresed markedly at the first hour of age and decreased therafter. Levels of f- <T_4> and f- <T_3> showed two peaks at 3 and 24 hours of age, then the former decreased and the latter increased toward 144 hours of age, indicat
… More
ing that the normal new born infant wolud be requested to keep hyperthyroidal situations physiologically, especially in the neonatal period for the survival in extra-uterine life.
2. Chracteristics of Placental Thyrotropins: Purifed hCG did not bind to TSH receptors prepared from human thyroid tissues, but asialo-hCG did, suggesting that hCG and hCG subunits did not show any thyrotropic activity, but asialo-hCG acts as an antagonist of TSH.
3. Direct Effects of Thyroid Hormones on Early Placenta and Granulosa Cells: Early placental tissues were cultured with <T_3> . Although <T_3> <10^(-7)> - <10^(-9)> M) caused significant increases of progesterone and estradiol secretions, excess amount ( <10^(-3)> M) decreased those secretions, suggesting that thyroid hormones play a physiological role in the maintenance of early pregnancy through their direct actions on steroidogenesis in placenta. Porcine granulosa cells obtained from small follicles were cultured in the absence and presence of porcine FSH for 6 days, with or without <T_4> or <T_3> . Concomitant treatment with FSH and <T_4> caused a increased production of progesterone or estrone in response to addition of pregnenolone or androstenedione, respectively. It can be concluded that synergism between FSH and thyroid hormones is of physiological importance to the full expression of FSH action in the functional differentiation of immature granulosa cells. Less
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