title: Human embryonic somatomedin.
abstract: A radioreceptor assay utilizing human fetal brain plasma membrane as matrix and somatomedin A as ligand (fetal brain RRA-SMA) was developed. Increased levels of fetal brain RRA-SMA were found in the fetal circulation. The concentration was approximately 4-fold higher in the fetal as compared to the adult human. At birth, values fell within the adult range. In contrast, adult somatomedins determined by somatomedin radioimmunoassay were undetectable in the fetus and below the adult range at birth. Levels of fetal brain RRA-SMA were decreased in fetuses with different clinical disorders. In healthy newborns at cesarean section a significant correlation between serum fetal brain RRA-SMA values and birth weight and length was found. These results indicate the presence of an embryonic somatomedin in humans. The fetal brain RRA-SMA may provide a reliable index of fetal growth.
mesh_terms: D000328:Adult; D001921:Brain / Q000196:embryology; D001923:Brain Chemistry; D002462:Cell Membrane / Q000032:analysis; D004622:Embryo, Mammalian / Q000502:physiology*; D005260:Female; D005312:Fetal Blood / Q000032:analysis*; D005865:Gestational Age; D006801:Humans; D008297:Male; D011247:Pregnancy; D011869:Radioligand Assay; D013002:Somatomedins / Q000097:blood*
chemical_list: D013002:Somatomedins