Characteristics of Serum Insulin-like Growth Factor ( IGF ) and IGF-Bindign Protein-3 during Pregnancy.
- Author:
Dae Yeol LEE
;
Jung Soo KIM
;
Hong Ro LEE
;
Cheol Hee RHEE
;
Soo Chul CHO
- Publication Type:Original Article
- Keywords:
IGF-I;
IGF-II;
free IGF-I;
IGFBP-3;
prenancy
- MeSH:
Blotting, Western;
Female;
Humans;
Insulin-Like Growth Factor Binding Protein 3;
Insulin-Like Growth Factor I;
Insulin-Like Growth Factor II;
Peptides;
Postpartum Period;
Pregnancy*;
Pregnant Women;
Radioimmunoassay;
Rodentia;
Somatomedins
- From:Journal of Korean Society of Endocrinology
1997;12(3):376-385
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Pregnancy in human and rodents is associated with dramatic matemal metabolic changes. Insulin-like growth factors (IGFs) are mitogenic peptides that are essential for fetal and maternal tissue growth during pregnancy. They circulate complexed primarily with a serum IGF-binding protein (IGFBP-3) which regulates the availability of the IGFs to their specific target tissues. METHODS: To examine the changes of IGFs and IGFB-3 during pregnancy, we measured serum total IGF-I, free IGF-I, IGF-II and IGFBP-3 by using specific radioimmunoassay, immunoradio-metric assay, western ligand blot and western immunoblot. Blood samples were obtained from 88 pregnant women between 6-40 weeks gestation. RESULTS: While serum IGF-I levels increased up to 50% in late pregnancy, serum IGF-II levels remained unchanged. However, serum free IGF-I levels were significantly higher during pregnancy than in nonpregnancy. Western ligand blot analysis revealed that IGFBP-3 in pregnancy serum was significantly decreased at 6 weeks of gestation, continued decreased level until term, and returned to a nonpregnant level by postpartum 10 day. Serum IGFBP-3 profiles in Western immunoblot analysis revealed that 30 kDa fragments of IGFBP-3 were detectable in pregnancy serum but not in nonpregnancy serum. In contrast, serum IGFBP-3 levels using radioimmunoassay was significantly increased in late pregnancy. CONCLUSIONS: 1) serum IGF-I was significantly elevated in late pregnancy 2) serum IGF-II was not significantly changed 3) free IGF-I significantly elevated throughout gestation 4) intact IGFBP-3 was markedly reduced after 6 weeks of gestation.
