Early membrane depressions in hepatocytes cultured on Primaria supports

The topography of spreading hepatocytes on positively charged Primaria plates was examined using scanning electron microscopy. The cells acquired a uniform morphology within 2 h. The spreading was rapid and the surface of the cells showed early prominent depressions or dips. The hepatocytes had either one or two of these structures which corresponded to the frequency of mononuclear and binuclear cells, respectively. The nuclear origin of the dips was strengthened after 6 h. They contained solid structures, whose number, size and shape were the same as nucleoli. The membrane dipping was independent of cell density and took place under conditions where phenotypic changes can occur. Kidney proximal tubule cells had no dips. Co-cultures of hepatocytes and kidney proximal tubule cells showed that the cell types behave differently.