Heterogeneity of insulin‐like growth factor binding proteins and relationships between structure and affinity

Hardouin, S; Hossenlopp, Paul; Segovia, Berta; Seurin, Danielle; Portolan, Ghyslaine; Lassarre, Claudine; Binoux, M

doi:10.1111/j.1432-1033.1987.tb13676.x

Cited by 175 publications

(68 citation statements)

References 35 publications

(14 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recent evidence, however, suggests that the biologic action of IGF-I is strongly modified by the relative concentrations of its binding proteins in plasma, amniotic fluid, and a variety of tissues (27)(28)(29)(30)(31)(32). Thus, a measurement in blood or tissue of the IGF-I concentration after removal of the binding proteins gives only one index of the biologic action of this growth factor.…”

Section: Resultsmentioning

confidence: 99%

Insulin-Like Growth Factor I in Substrate-Deprived, Growth-Retarded Fetal Rats

1991

View full text Add to dashboard Cite

ABSTRACF. Plasma, amniotic fluid, and tissue concentra-Control animals were allowed free access to both food and water. tions of IGF-I were examined in nutritionally deprived, Sampling was performed on d 2 1 in all animals, after intraperigrowth-retarded fetal rats to determine whether IGF-I toneal pentobarbital (45 mg/kg) administration. Midline lapaconcentration serves as a marker for nutritional status. rotomy incision was used to expose the uterine horns. Fetuses in Growth retardation was induced by 72 h of maternal fast-each horn were counted, and the two inferior fetuses of each ing. Twenty-three control and 17 growth-retarded fetuses horn were sampled to match the control and test group with were individually analyzed and compared. Plasma IGF-I regard to intrauterine location. A maximum of four fetuses per concentrations were significantly lower in test compared dam were analyzed to insure matching of uterine location bewith control animals (test 56.8 f 14.9, control 87.4 f 17.5 tween groups and to minimize any metabolic impact of the ng/mL, p < 0.01). Amniotic fluid IGF-I concentrations surgical procedure. Only those fetuses in whom results from all were not different (test 14.0 f 8.7, control 12.2 f 2.6 ng/ specimens were available were included in the analyses. The mL). IGF-I concentrations obtained from both placental sampling sequence was initiated by the removal of amniotic fluid and hepatic tissues were lower in test compared with with a 19-or 20-gauge 1-mL syringe. The fetus was then removed control animals [placenta: test 293 f 25 versus control 655 from its location in the uterine horn, and an axillary cutdown f 114 ng/g (p < 0.001); hepatic: test 173 k 38 versus was performed (15). Fetal blood was collected by heparinized control 230 f 51 ng/g ( p < 0.01)]. Reductions in fetal, capillary tube, placed on ice, and centrifuged for 15 min at 12 placental, and hepatic weights in test animals were more 000 X g. The fetus was separated from the placenta, and the closely related to changes in placental IGF-I concentration fetus, placenta, and then fetal liver were weighed. The placenta than to either plasma or hepatic IGF-I concentrations. We and liver were quickfrozen in liquid nitrogen. All samples were conclude that fetal plasma IGF-I is a valuable marker for stored at -80°C until analysis. After fetal sampling, a maternal intrauterine substrate deprivation and that the growth-venous plasma sample was obtained from the inferior vena cava retarded rat fetus is accurately identified and specifically just below the renal vein. Euthanasia was performed by means characterized by a low placental concentration of extract-of exsanguination after all samples had been obtained. Individual Analyses. IGF-I concentrations in maternal and fetal plasma and amniotic fluid were determined by RIA [National Institute Circulating concentrations of IGF-I are influenced by both of Diabetes and Digestive and Kidney Diseases somatomedin-C growth hormone and nutritional status (1-10). Although the antiserum (polyclonal) cod...

show abstract

Section: Resultsmentioning

confidence: 99%

Insulin-Like Growth Factor I in Substrate-Deprived, Growth-Retarded Fetal Rats

1991

View full text Add to dashboard Cite

show abstract

“…The hepatic form has recently been cloned from a liver cDNA library and named IGFBP-2 (49). The 34-, 30-, and 24-kD BP associate with IGF to form only binary complexes (22).…”

Section: Bp (Or Igf-bp) Igf Binding Proteinmentioning

confidence: 99%

Serum Insulin-Like Growth Factors and Insulin-Like Growth Factor Binding Proteins in the Human Fetus. Relationships with Growth in Normal Subjects and in Subjects with Intrauterine Growth Retardation

et al. 1991

Self Cite

View full text Add to dashboard Cite

ABSTRACT'. IGF-I, IGF-11, and their binding proteins (BP) were studied in sera obtained by direct puncture of umbilical cords in utero between 20 and 37 wk of gestation in 103 normal fetuses and in 16 fetuses with intrauterine growth retardation, as well as in the cord blood of 37 normal newborns of 38-to 42-wk pregnancies. In normal fetuses, IGF-I levels were approximately 50 ng/mL and IGF-I1 levels approximately 350 ng/mL up to the 33rd wk of pregnancy. Thereafter, both increased to reach values two to three times higher at term. Correlations were found between fetal placental lactogen levels and those of IGF-I and IGF-11, which is consistent with the hypothesis that placental lactogen is involved in the regulation of IGF synthesis in the fetus. With weight (either measured at birth or deduced from echographical data) as index of fetal size, IGF-I levels were significantly ( p < 0.001) higher in fetuses with weights above the mean for gestational age than in fetuses with weights below the mean, whereas IGF-I1 levels were similar in the two groups. Similarly, IGF-I (but not IGF-11) levels in fetuses with intrauterine growth retardation were significantly lower than those in normal fetuses of the same age ( p < 0.01). These findings suggest that, during the latter months of intrauterine life, IGF-I (but not IGF-11) is involved in the control of fetal size. Total fetal BP concentrations were approximately '/J those of adults. The fetal electrophoretic profile obtained by Western-ligand blotting bore a strong resemblance to that of subjects with growth hormone deficiency. In newborns, the proportions of IGF-I and IGF-I1 associated with BP to form 150-kD complexes were considerably lower than those in adults, but similar to those in hypopituitary patients. It may be deduced from these findings that during fetal life, BP synthesis is adapted to increase the bioavailability of the IGF at a time when growth is at a maximum.

show abstract

“…Following a 2-h preincubation period, samples (0·08-6·25 mg protein/l) were treated with 4 µl 25 mM DSS in DMSO (final concentration 0·25 mM) for 30 min at room temperature. Samples (25 µl) were prepared for SDS-PAGE by addition of 25 µl sample buffer (5% SDS, 10% glycerol, 0·06 M Tris-HCl pH 6·8, 5% 2-mercaptoethanol, and 0·02% bromophenol blue; final concentrations) and heated at 60 C for 15 min (Hardouin et al 1987 …”

Section: I]igf-i Binding Studiesmentioning

confidence: 99%

Contribution of insulin-like growth factor (IGF)-I and IGF-binding protein-3 to mitogenic activity in bovine mammary extracts and serum

Ms¹,

Purup²,

Vestergaard³

et al. 1999

Journal of Endocrinology

View full text Add to dashboard Cite

Peripubertal development of the mammary gland is probably mediated by locally produced growth factors acting in concert with circulating mitogens. Our objective was to investigate the effect of recombinant human insulin-like growth factor-binding protein-3 (rhIGFBP-3) or insulin-like growth factor-I (IGF-I) antibodies on the IGF-I-related mitogenic activity of bovine serum and of mammary tissue extracts in primary mammary epithelial cell cultures. Cells were obtained from prepubertal female calf mammary tissue and cultured in three-dimensional collagen gels. An aqueous mammary parenchymal tissue extract (pooled from 20 prepubertal heifers) or serum (pooled from 3 heifers) at a concentration of 5% was added to the medium containing either rhIGFBP-3 or monoclonal or polyclonal antibodies to human IGF-I. Cell proliferation was evaluated using [methyl-3 H]thymidine incorporation as a measure of DNA synthesis. Addition of mammary extracts stimulated DNA synthesis 545% compared with basal medium. Addition of serum stimulated DNA synthesis by 28%. Mitogenic activity of serum and added IGF-I was abolished by addition of rhIGFBP-3 in equimolar concentrations with IGF-I. For mammary extracts, mitogenic activity was inhibited by 35%, 50%, and 82% by the addition of rhIGFBP-3 at, respectively, 1, 2 and 4 times the molar IGF-I concentration in the extract. Addition of rhIGFBP-3 to basal medium reduced DNA synthesis by 26%, whereas IGF-I antibodies had no consistent effect. These results indicate that circulating and mammary-synthesized IGF-I and IGFBPs probably play a critical role in prepubertal development of the bovine mammary gland.

show abstract

Heterogeneity of insulin‐like growth factor binding proteins and relationships between structure and affinity

Cited by 175 publications

References 35 publications

Insulin-Like Growth Factor I in Substrate-Deprived, Growth-Retarded Fetal Rats

Insulin-Like Growth Factor I in Substrate-Deprived, Growth-Retarded Fetal Rats

Serum Insulin-Like Growth Factors and Insulin-Like Growth Factor Binding Proteins in the Human Fetus. Relationships with Growth in Normal Subjects and in Subjects with Intrauterine Growth Retardation

Contribution of insulin-like growth factor (IGF)-I and IGF-binding protein-3 to mitogenic activity in bovine mammary extracts and serum

Contact Info

Product

Resources

About