LOCALIZATION OF ALPHA-FETOPROTEIN AND ALBUMIN IN PIG-LIVER DURING FETAL AND NEONATAL DEVELOPMENT

The localization of hepatocytes containing α-fetoprotein (AFP) and albumin during the fetal and neonatal development of the pig has been studied with the aid of indirect immunofluorescence technique. AFP was found in all hepatocytes in pig fetuses with crown to rump lengths (CR lengths) of 2-25 cm and in neonatal pigs during the first 5 days of extrauterine life. On the sixth day after birth, AFP-negative hepatocytes appear in the periphery of the liver lobules. No AFP-containing cells could be observed in livers of adult pigs. Contrary to AFP, albumin was found only in a small portion of hepatocytes during early fetal development. This portion increases during development, and albumin is found in all hepatocytes in fetuses with CR lengths of 14 cm and more. After birth the staining intensity for albumin increases markedly, and in contrast to AFP, all hepatocytes in 6-day-old pigs contain albumin irrespective of their localization in the liver lobule. The results indicate that the AFP-producing hepatocytes successively acquire the ability to produce albumin during fetal development. Evidently AFP and albumin are produced by the same cells. During neonatal development the AFP/albumin-producing hepatocytes seem to cease their production of AFP, as hepatocytes containing albumin but no detectable amounts of AFP appear at the border of each liver lobule 5-6 days after birth. © 1979 Academic Press, Inc.