Phenobarbital metabolism by hepatocytes isolated from rat.
In order to test the validity of the use of hepatocytes as an alternative to studies of metabolism in live animals, phenobarbital (PB) was applied at 37 degrees C to isolated rat hepatocytes, which had been previously induced by PB. The metabolites were extracted by ethyl acetate, at various pH, and identified and evaluated by GC-MS. PB was not metabolized to p-hydroxyphenobarbital as is usually the case in living animals, but it was transformed into sulphoconjugated 2-phenyl-gamma-butyrolactone. This pathway, beta-hydroxylation of the ethyl side chain followed by lactonization, previously described as a secondary metabolic pathway occurring during intoxications, was here the only observed biodegradation. These results show that it is not possible to use hepatocytes as an alternative to live animals.
Laboratoire de Pharmacochimie et Biopharmacie, Faculté de Médecine et de Pharmacie de Rouen, Saint-Etienne-du-Rouvray, France.
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Farnoux
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Lafont
D000826:Animal Testing Alternatives; D000818:Animals; D001711:Biotransformation; D002138:Calibration; D002849:Chromatography, Gas; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D005966:Glucuronidase / Q000378:metabolism; D006900:Hydroxylation; D006993:Hypnotics and Sedatives / Q000378:metabolism*; D066298:In Vitro Techniques; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D010634:Phenobarbital / Q000031:analogs & derivatives / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013429:Sulfatases / Q000378:metabolism
D006993:Hypnotics and Sedatives; C017414:4-hydroxyphenobarbital; D013429:Sulfatases; D005966:Glucuronidase; D010634:Phenobarbital