| Project/Area Number |
06671692
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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 | Tokyo Women's Medical College |
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Principal Investigator |
IWASHITA Mitsutoshi Tokyo Women's Medical College, Dept.of OB/GYN,Associate Professor, 医学部, 助教授 (30124936)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAI Keiji Tokyo Women's Medical College, Dept.of OB/GYN,Assistant, 医学部, 助手 (30260962)
KUDO Yoshiki Tokyo Women's Medical College, Dept.of OB/GYN,Assistant Professor, 医学部, 講師 (80241082)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1995: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1994: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Growth factor / Fetus / Growth / IGF / IGF-binding protein / Phosphorylation / Metabolism / 胎児発育 |
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| Research Abstract |
Insulin-like growth factor-I (IGF-I) is one of growth factors that circulates bound to specific, high affinity binding proteins (IGFBPs). One of IGFBPs, IGFBP-1 is known to be phosphorylated in biological fluid, however, the physiological significance of phosphorylation on this molecle is not elucidated. We investigated the effect of phosphorylation of IGFBP-1 on fetal growth in this study.
The isomers of phosphorylated IGFBP-1 in fetal rats and cord sera are separated by immunoblot and anion ion exchange chromatography in which one nonphosphorylated and four phosphorylated IGFBP-1 are detected. In pared blood samples from mid-term delivery, percentage of nonphosphorylated IGFBP-1 is higher in fetal blood compared to those in mother. Similarly, percentage of nonphosphorylated IGFBP-1 is elevated in AFD infants than in SFD infants from term delivery. Thus, the proportion of nonphosphorylated and phosphorylated isomers of IGFBP-1 varies corresponding to fetal growth.
The affinity of phosphorylated IGFBP-1 for IGF-I is 4-fold higher than those of nonphosphorylated IGFBP-1 when evaluated by binding study.
Nonphosphorylated IGFBP-1 enhances IGF-I-mediated ^3H-AIB uptake by cultured trophoblast cells while phosphorylated IGFBP-1 inhibits when cells are incubated with IGF-I under the presence of these isoforms of IGFBP-1.
Thus, phosphorylated and nonphosphorylated IGFBP-1 have differant biochemical property and modify IGF-I action differntly.
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