The cytoskeleton of digitonin-treated rat hepatocytes.

Abstract

Treatment of isolated rat hepatocytes with low concentrations of digitonin increases the permeability of the plasma membrane to cytosolic proteins without causing release of organelles i.e., mitochondria into the surrounding medium. EM showed that treatment of the cells with increasing concentrations of digitonin causes a progressive loss in the continuity of the plasma membrane, while most other aspects of cellular morphology remain normal. Depletion of background staining material from the cytosol by digitonin treatment of the cells greatly enhances the visualization of the cytoskeleton. The use of this technique, together with immunofluorescent light microscopy, has verified the presen ce of an actin-containing filamentous network at the hepatocyte cortex and intermediate filaments distributed throughout the cell. Digitonin is useful both for selectively permeabilizing the plasma membrane and for intensitying the appearance of intracellular structures, i.e., microfilaments that are normally difficult to observe in cells, i.e., hepatocytes.