Immunohistochemical study of alpha-fetoprotein and serum albumin in the early postnatal period in mice.

The localization of the embryo-specific protein alpha-fetoprotein (alpha-FP) and serum albumin in the organs of mice in the first three weeks of life was studied. Using a reaction of immunofluorescence, alpha-FP was detected in the cytoplasm of the hepatocytes. During the first three days of life it was contained in the overwhelming majority of the hepatocytes, but in different concentrations. Then the fluorescence intensity and number of cells containing alpha-FP decreased sharply, and by the seventh to 12th day such cells remained chiefly close to the central veins. In a simultaneous determination of alpha-FP and albumin in the liver, cells containing only alpha-FP, alpha-FP and albumin, and only albumin were detected. With increasing age of the animals, the number of the latter cells increased. On slices of other organs, alpha-FP, albumin, and transferrin were present in the same structures of gamma-globulin.