Changes in liver cell plasma membrane polypeptides of phalloidin-treated rats with special reference to the actomyosin complex.

Studies on isolated liver cell plasma membranes enriched in bile canaliculi from male rats treated with phalloidin show marked changes in the membrane polypeptides. Upon examination by sodium dodecyl sulfate polyacrylamide gel electrophoresis, a protein component identical in mobility to the myosin standard was dramatically reduced, while that corresponding to actin was increased. It is suggested that a myosin-like protein may be necessary for the contractile function of the actin filaments in the liver cells. The observed modifications may be related to the decreased bile secretion and dilatation of bile canaliculi induced by phalloidin.