title: Vesicle movement in rat hepatocytes is reduced by ethanol exposure: alterations in microtubule-based motor enzymes.
abstract: OBJECTIVE
  Ethanol is known to alter vesicle-mediated protein trafficking in hepatocytes by undefined mechanisms. In this study, the effects of long- and short-term ethanol exposure on vesicle movements were measured in isolated hepatocytes, and alterations in the function of the microtubule-associated motor enzymes dynamin, kinesin, and dynein, which are believed to support the transport and/or budding of vesicles along microtubules, were tested.
  
  
  METHODS
  Vesicular movements in isolated hepatocytes exposed to short- and long-term ethanol treatment were measured. Motor adenosine triphosphatase activities and their association with specific membrane organelles were assessed in response to long-term administration of ethanol in vivo or acetaldehyde in vitro.
  
  
  RESULTS
  Hepatocytes exposed to short- or long-term ethanol treatment showed a significant reduction in the number of motile vesicles. No alterations in the levels of motor messenger RNA, protein, or enzymatic activity were observed. Interestingly, ethanol had no effect on the association of dynein and kinesin with membranes, whereas there was a significant increase in the amount of dynamin associated specifically with Golgi membranes.
  
  
  CONCLUSIONS
  Long- and short-term ethanol exposure markedly reduces hepatocellular vesicle transport by a mechanism apparently independent of any alteration in the enzymatic activity of molecular motors, possibly involving a change in the function of dynamin.
authors.affiliation: Center for Basic Research in Digestive Diseases, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: N
authors.initials: N
authors.lastname: Török
authors.forename: D
authors.initials: D
authors.lastname: Marks
authors.forename: K
authors.initials: K
authors.lastname: Hsiao
authors.forename: B J
authors.initials: BJ
authors.lastname: Oswald
authors.forename: M A
authors.initials: MA
authors.lastname: McNiven
mesh_terms: D000079:Acetaldehyde / Q000494:pharmacology; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D034281:Dynamins; D004398:Dyneins / Q000235:genetics / Q000378:metabolism; D000431:Ethanol / Q000494:pharmacology*; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism; D007425:Intracellular Membranes / Q000187:drug effects* / Q000502:physiology*; D016547:Kinesins / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000166:cytology* / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D008870:Microtubules / Q000201:enzymology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D012333:RNA, Messenger; D000431:Ethanol; D000251:Adenosine Triphosphatases; D020558:GTP Phosphohydrolases; D004398:Dyneins; D016547:Kinesins; D034281:Dynamins; D000079:Acetaldehyde