Estrogen-induced ultrastructural changes in cultured chick embryo hepatocytes.

Administration of estradiol-17-beta induces the synthesis of vitellogenin in primary cultures of chick embryo liver. The ultrastructural changes accompanying steroid induced vitellogenin synthesis were investigated in hepatocytes cultures incubated for 0, 12 and 24 h following hormonal treatment. Both electron microscopy and immuno-chemical techniques were used. The immuno-fluorescence data indicate that the cultures contain a cell population of 90--95% hepatocytes, both in control and estradiol-treated groups. Ultrastructurally, cultured hepatocytes are similar to in vivo ones, except for a reduced accumulation of storage materials, glycogen and lipids. In the estradiol-treated cultures hepatocytes show an accumulation of free ribosomes, enlargement of rough endoplasmic reticulum, and development of the Golgi apparatus.