Ontogenesis of somatomedin and insulin receptors in the human fetus.

Abstract

A C T This study examines the ontogenesis of somatomedin and insulin receptors in man. Particulate plasma membranes were prepared by ultracentrifu- gation from various tissues removed from fetuses after abortion and classified as <17, 17-25, and >25 cm in length. The binding of iodinated insulinlike growth factors 1 (IGF-1) and 2 (IGF-2), somatomedin A (SMA), multiplication-stimulating activity (MSA), and insulin was examined at the different ages.