Measurement of somatomedin-related peptides in fetal, neonatal, and maternal rat serum by insulin-like growth factor (IGF) I radioimmunoassay, IGF-II radioreceptor assay (RRA)
Previous measurements of somatomedins (Sms) and insulin-like growth factors (IGFs) in maternal and fetal serum have yielded contradictory results. We have, therefore, measured maternal, fetal, and neonatal rat serum with two highly specific assays: 1) IGF-I/Sm-C RIA and 2) a highly specific IGF-II/rat placental membrane radioreceptor assay (RRA). In addition, we have made measurements with a less specific multiplication-stimulating activity (MSA)-rat placental membrane RRA. To avoid possible serious artifacts created by Sm-binding proteins, preliminary acid-ethanol extraction of serum was performed. Results are expressed in terms of a reference human serum with an assigned potency of 1 U/ml. We now conclude that radioimmunoassayable IGF-I is present in higher concentrations than previously reported interm fetal rat serum and that radioreceptor assayable IGF-II is selectively elevated in rat fatal and neonatal life and may have unique metabolic and rowth-promoting significance.
- Research Organization:
- Washington University School of Medicine, St. Louis, MO
- OSTI ID:
- 5579229
- Journal Information:
- Endocrinology; (United States), Vol. 110:2
- Country of Publication:
- United States
- Language:
- English
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PEPTIDES
RADIOIMMUNOASSAY
RADIORECEPTOR ASSAY
BLOOD SERUM
EXTRACTION
FETUSES
GROWTH
MEASURING METHODS
NEONATES
RATS
STIMULATION
ANIMALS
ISOTOPE APPLICATIONS
MAMMALS
ORGANIC COMPOUNDS
PROTEINS
RADIOASSAY
RODENTS
SEPARATION PROCESSES
TRACER TECHNIQUES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques