Insulin binding and internalization in rat hepatocytes during prenatal and postnatal life.

Insulin binding to isolated rat hepatocytes was studied during prenatal and postnatal life. Results show that in hepatocytes isolated from prenatal, postnatal and adult rat there is a constant increase in the number of insulin binding sites per cell, whereas the affinity of plasma membrane receptors for the hormonal ligand remains unaltered from prenatal to adult hepatocytes. Autoradiographic studies indicate a greater internalization of hormone during prenatal life and, taking into account the increase of cell size, suggest an unchanged surface density of receptor sites before and after birth.