DYNAMICS OF ALPHA-FETOPROTEIN AND ALBUMIN SYNTHESIS IN HUMAN AND RAT-LIVER DURING NORMAL ONTOGENY

Abstract

Immunocytochemical localization of each protein in the liver and its quantitation in serum at different periods of normal intrauterine and extrauterine life were studied. The proteins were present only in the cytoplasm of hepatocytes. During physiologic development, in inverse relationship existed between the serum concentrations of the 2 proteins, the latter for each appearing to be directly related to the number of hepatocytes synthesizing it. AFP[.alpha.-fetoprotein]-containing cells were randomly distributed, while albumin-containing cells were more uniformly spread out. Both were often preferentially located around venous channels. In the case of AFP-containing cells, the last to disappear with advancing postnatal age were seen around the hepatic veins. When both proteins were present in serum, several hepatocytes seemed to synthesize the 2 simultaneously, though others contain only 1 of them. It was unlikely that in the physiologic state different populations of hepatocytes were assigned to synthesize AFP and albumin separately.