Bile canalicular contraction is coincident with reorganization of pericanalicular filaments and co-localization of actin and myosin-II

J Histochem Cytochem. 1993 Mar;41(3):353-63. doi: 10.1177/41.3.7679126.


We examined the relationships between actin-myosin interaction and bile canalicular contraction using a new experimental model: cytoskeleton-enriched canalicular membranes (CCM). In CCM, the bile canaliculus compartment is isolated complete with membrane-attached pericanalicular actin filaments and the surrounding intermediate filament sheath. Immunofluorescence and immunoelectron microscopy showed that actin and myosin-II were distributed over pericanalicular microfilaments that insert into adherens (belt) junctions; intermediate filaments predominantly inserted into desmosomes. The addition of "contraction solution" (1 microM Ca2+, 1 mM ATP) resulted in closure of CCM lumens, which was interpreted as canalicular contraction. Contraction was also associated with shortening and/or twisting of canaliculi. Rearrangement of actin filaments and myosin-II with co-localization of actin and myosin was observed. Evidence is also provided for attachment of actin-myosin-II aggregates to intermediate filaments coincident with contraction, suggesting a key scaffold function for intermediate filaments of the canaliculus. Attention is drawn to the overall similarity of structure-function dynamics in hepatic apical membranes to those described in intestinal brush border membrane preparations. The results are consistent with dynamic actin-myosin interaction with co-localization of actin and myosin-II in filament clumps coincident with canalicular contraction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / chemistry
  • Actin Cytoskeleton / ultrastructure*
  • Actins / analysis*
  • Animals
  • Bile Canaliculi / chemistry
  • Bile Canaliculi / physiology*
  • Bile Canaliculi / ultrastructure
  • Female
  • Immunohistochemistry
  • Intermediate Filaments / chemistry
  • Intermediate Filaments / ultrastructure*
  • Keratins / analysis
  • Microscopy, Electron
  • Microscopy, Fluorescence
  • Microscopy, Immunoelectron
  • Myosins / analysis*
  • Rats
  • Rats, Wistar


  • Actins
  • Keratins
  • Myosins