title: The 3alpha-hydroxy-steroid-dehydrogenase-mRNA and -protein are more prevalent in pericentral than in periportal hepatocytes.
abstract: BACKGROUND
  Under physiological conditions, de-novo synthesis and metabolism of bile acids are confined mainly to the pericentral zone of the liver acinus. In the rat, 3alpha-hydroxy-steroid-dehydrogenase (3alpha-HSD) is the major bile acid-binding protein. At the same time, this protein is involved in the de-novo synthesis and metabolism of bile acids. Because bile acid processing is greater in the pericentral than in the periportal region, we investigated whether 3alpha-HSD is more prevalent in the pericentral than in the periportal area.
  
  
  METHODS
  We determined the 3alpha-HSD-protein and its mRNA in periportal and pericentral rat cells.
  
  
  METHODS
  Rat hepatocytes from the periportal or pericentral areas were isolated using the digitonin perfusion technique. For Northern blotting, a labelled 1.3-kb cDNA insert corresponding to the mRNA sequence of 3alpha-HSD was used. For Western blotting, a polyclonal rabbit antiserum against human 3alpha-HSD was used. Blots were quantified by densitometry using phosphoimaging.
  
  
  RESULTS
  The amounts of the 3alpha-HSD-protein and its mRNA were significantly greater in the pericentral than in the periportal cells.
  
  
  CONCLUSIONS
  The greater occurrence of 3alpha-HSD in pericentral than in periportal hepatocytes is in line with the concept that bile acid synthesis and metabolism take place predominantly in pericentral cells.
authors.affiliation: Department of General Surgery, University of Freiburg, Germany. baumgart@chir.ukl.uni-freiburg.de
authors.forename: Ulrich
authors.initials: U
authors.lastname: Baumgartner
authors.forename: Peter
authors.initials: P
authors.lastname: Baier
authors.forename: Oliver
authors.initials: O
authors.lastname: Birke
authors.forename: Eduard H
authors.initials: EH
authors.lastname: Farthmann
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D022781:Hepatocytes / Q000201:enzymology*; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D012333:RNA, Messenger; D015096:3-Hydroxysteroid Dehydrogenases