Premium
STUDIES OF INSULIN‐LIKE GROWTH FACTOR ‐I AND ‐II BY SPECIFIC RADIOLIGAND ASSAYS IN UMBILICAL CORD BLOOD
Author(s) -
GLUCKMAN P. D.,
JOHNSONBARRETT J. J.,
BUTLER J. H.,
EDGAR B. W.,
GUNN T. R.
Publication year - 1983
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1111/j.1365-2265.1983.tb00014.x
Subject(s) - somatomedin , radioimmunoassay , endocrinology , medicine , insulin like growth factor , gestational age , umbilical cord , fetus , growth factor , insulin , birth weight , insulin like growth factor 2 , biology , pregnancy , receptor , immunology , genetics
SUMMARY Somatomedin concentrations in human umbilical sera ( n = 206) were measured using a specific radioimmunoassay for insulin‐like growth factor (IGF)‐I and a specific radioreceptor assay for IGF‐II following acid‐ethanol extraction of the sera to remove the somatomedin binding proteins. IGF‐I concentrations were lower ( P < 0·001) than adult values and correlated with gestational age ( P < 0·001) and birth weight ( P < 0·0001). Multiple regression analysis demonstrated that both birth weight expressed independently of gestational age as the standard deviate score ( P < 0·0001) and gestational age ( P < 0·002) had effects on umbilical cord IGF‐I concentrations. IGF‐II concentrations were similar to adult values and did not correlate with gestational age, birth size or IGF‐I values. IGF‐II concentrations were higher ( P < 0·005) in male than female fetuses. These data support a role for IGF‐I in influencing fetal growth and suggest the independent regulation of the secretion of IGF‐I and II in the perinatal period. These was no evidence to suggest a distinct perinatal form of somatomedin.