Disappearance of visible bile canaliculi caused by vinblastine in primary cultures of rat hepatocytes.

Treatment of cultured hepatocytes with vinblastine resulted in the inhibition of the reformation of biliary spaces (at times earlier than 16 h) or in the disappearance of preformed bile canaliculi (at times later than 24 h) detectable on both the light and electron microscopical level. Concomitantly the preferential localization of leucine aminopeptidase around the lucid biliary spaces was lost without any change in the specific activity of this enzyme. Despite these alterations the performance of the cultured cells (e.g., urea synthesis) was not impaired by the exposure to the drug. The effect of vinblastine was mimicked by colchicine, but not by lumicolchicine, indicating that microtubules might play a role in the structural organization of the biliary pole.