title: Partial maintenance of taurocholate uptake by adult rat hepatocytes cultured in a collagen sandwich configuration.
abstract: OBJECTIVE
  This study was designed to characterize taurocholate uptake properties in primary cultures of rat hepatocytes maintained under different matrix conditions.
  
  
  METHODS
  Hepatocytes isolated from male Wistar rats (230-280 g) were cultured on a simple collagen film, on a substratum of gelled collagen or between two layers of gelled collagen (sandwich configuration). Hepatocyte morphology, taurocholate uptake properties, and expression of the sinusoidal transport protein. Na+/taurocholate-cotransporting polypeptide (Ntcp) were examined in these cultures at day 0 and day 5.
  
  
  RESULTS
  By day 5, monolayer integrity had deteriorated in simple collagen cultures. In contrast, cell morphology was preserved in hepatocytes maintained in a sandwich configuration. At day 5, taurocholate accumulation at 5 min in hepatocytes cultured on a simple collagen film, on a substratum of gelled collagen, and in a sandwich configuration was approximately 13%, 20% and 35% of day-0 levels, respectively, and occurred predominately by a Na+-dependent mechanism. The initial taurocholate uptake rate vs. concentration (1-200 microM) profile was best described by a combined Michaelis-Menten and first-order function. In all cases, the estimated apparent Km values were comparable for day-0 and day-5 hepatocytes (3241 microM). In contrast, the Vmax values of hepatocytes cultured on a simple collagen film, on gelled collagen and in a sandwich configuration were approximately 5, 6 and 14% of the values at day 0, respectively; values for the first-order rate constant were 5-, 3- and 2-fold lower, respectively. Immunoblot analysis indicated that at day 5 Ntcp expression in hepatocytes cultured in a sandwich configuration was greater than in hepatocytes cultured on a simple collagen film.
  
  
  CONCLUSIONS
  A collagen sandwich configuration reestablishes normal morphology and partially restores bile acid uptake properties in primary cultures of rat hepatocytes.
authors.affiliation: Division of Drug Delivery and Disposition, School of Pharmacy, University of North Carolina at Chapel Hill, 27599, USA.
authors.forename: X
authors.initials: X
authors.lastname: Liu
authors.forename: K L
authors.initials: KL
authors.lastname: Brouwer
authors.forename: L S
authors.initials: LS
authors.lastname: Gan
authors.forename: K R
authors.initials: KR
authors.lastname: Brouwer
authors.forename: B
authors.initials: B
authors.lastname: Stieger
authors.forename: P J
authors.initials: PJ
authors.lastname: Meier
authors.forename: K L
authors.initials: KL
authors.lastname: Audus
authors.forename: E L
authors.initials: EL
authors.lastname: LeCluyse
mesh_terms: D000818:Animals; D001692:Biological Transport; D002478:Cells, Cultured; D003094:Collagen / Q000494:pharmacology*; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013656:Taurocholic Acid / Q000493:pharmacokinetics*
chemical_list: D013656:Taurocholic Acid; D003094:Collagen