Xenobiotic metabolism by cultured primary porcine hepatocytes.
Considering the large yield of viable cells comparable to human liver, primary porcine hepatocytes offer a valuable resource for constructing a bioartificial liver device. In this study, the ability of cultured primary porcine hepatocytes to detoxify xenobiotics has been examined using various known substrates of cytochrome P450 isoenzymes and UDP-glucuronosyltransferases. Present investigation demonstrated the stability of the isoenzymes responsible for the metabolism of diazepam in native state and stabilization of other isoenzymes, as judged by ethoxycoumarin o-dealkylase (ECOD), ethoxyresorufin o-dealkylase (EROD), benzyloxyresorufin o-dealkylase (BROD), and pentoxyresorufin o-dealkylase (PROD) activities following induction in culture environment, for a period of 8 days. Resorufin O-dealkylase activities were found to be the most unstable and deteriorated within first 5 days in culture. These activities were restored following induction with 3-methylcholanthrene (3-MC) or sodium phenobarbital (PB) to 20-fold of 1 activity for EROD, and 60 and 174% of day 1 activity for PROD and BROD on day 8, respectively. Metabolism of methoxyresorufin was most strikingly increased following induction with 3-MC to approximately 60-fold of day 1 activity, on day 8. UDP-glucuronosyltransferase-dependent glucuronidation of phenol red, however, stayed intact during the course of our study without induction. Our study indicated that porcine hepatocytes in vitro maintain many important liver-specific functions including detoxification (steady state and inducibility).
Behnia
K
K
Centre for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School and Shriners Hospitals for Children, Boston, Massachusetts 02114, USA.
Bhatia
S
S
Jastromb
N
N
Balis
U
U
Sullivan
S
S
Yarmush
M
M
Toner
M
M
D015660:7-Alkoxycoumarin O-Dealkylase / Q000378:metabolism; D000418:Albumins / Q000378:metabolism; D000818:Animals; D002469:Cell Separation / Q000379:methods; D002478:Cells, Cultured; D003374:Coumarins / Q000493:pharmacokinetics; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D019362:Cytochrome P-450 CYP2B1 / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D003975:Diazepam / Q000493:pharmacokinetics; D001728:Dicumarol / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004790:Enzyme Induction; D004791:Enzyme Inhibitors / Q000494:pharmacology; D014453:Glucuronosyltransferase / Q000378:metabolism; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008658:Inactivation, Metabolic; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D010078:Oxazines / Q000493:pharmacokinetics; D010088:Oxidoreductases / Q000378:metabolism; D010637:Phenolsulfonphthalein / Q000493:pharmacokinetics; D051381:Rats; D011917:Rats, Inbred Lew; D013552:Swine; D014508:Urea / Q000378:metabolism; D015262:Xenobiotics / Q000493:pharmacokinetics
D000418:Albumins; D003374:Coumarins; D004791:Enzyme Inhibitors; D010078:Oxazines; D015262:Xenobiotics; C017299:7-ethoxycoumarin; C014180:resorufin; D001728:Dicumarol; D014508:Urea; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; C076307:methoxyresorufin-O-demethylase; D015660:7-Alkoxycoumarin O-Dealkylase; D019363:Cytochrome P-450 CYP1A1; D019362:Cytochrome P-450 CYP2B1; D014453:Glucuronosyltransferase; D010637:Phenolsulfonphthalein; D003975:Diazepam