Effect of cytochalasin B and phalloidin on actin and myosin of primary cultured rat hepatocytes.

Alterations of actin and myosin were observed by the effects of cytochalasin B (CB) and phalloidin (Ph) using primary cultured rat hepatocytes. The morphology of cells was observed by phase contrast microscopy and actin was observed by fluorescent microscopy using DACM-HMM. Myosin was observed by immunofluorescence techniques using anti-rat liver myosin antibody. In normal controls, after a 3hour incubation, actin and myosin were both intensely observed in the region along the plasma membrane, especially around the bile canaliculi. After a 24hour incubation, hepatocytes spread and actin and myosin were observed around the bile canaliculi, and appeared as filamentous patterns in the cytoplasm. In the CB group, hepatocytes did not spread even after 24hours, and actin and myosin were identified as granules around the widely dilated bile canalicli. Filamentous patterns of actin and myosin were not observed in the cytoplasm. In the Ph group, cytoplasmic vacuoles and protrusions from the cell membrane were observe. The hepatocytes did not spread even after a 24 hour incubation. Actin and myosin were identified as granules in the region along the plasma membrane, especially around the bile canaliculi. Present studies show that actin and myosin distribute almost to the same place in the hepatocytes and the integrity of each component of the cytoskeleton is important for normal cellular function.