An immunofluorescent study of alpha-fetoprotein. I. Its ontogenic development in human conceptus

A development of alpha-fetoprotein-producing tissues was investigated in 52 cases of human conceptuses ranging from 2 to 7 months in gestation by a fluorescent antibody technique. It is synthesized in endodermal cells of the yolk sac, hepatocytes including the cells of large bile canaliculi, and some gland epithelial cells of the stomach, while its accumulation also occurs in mesenchymal cells of the yolk sac and Kupffer cells of the liver. A mode of its localization in individual tissues was described and possible explanation on the origin of its producers was discussed.