A preliminary comparison of LiverBeads (TM) with a conventional rat hepatocyte culture preparation: Some aspects of xenobiotic metabolism and relatedtoxicity

LiverBeads(TM) are made of hepatocytes that are immobilised and cryopreserv ed in alginate gel. They have great potential as an easily transportable an d easily handled source of hepatocytes for use in in vitro pharmacotoxicolo gy. In this study, we compared the drug metabolising capacity of LiverBeads in culture with that of conventional cultures and of cultures derived from cryopreserved cells. Trypan blue exclusion, lactate dehydrogenase and DNA content were measured in LiverBead cultures. The levels were all similar to those of the conventional cultures, as were the toxicities of precocene II and allyl alcohol, although more variability was seen in the LiverBeads th an in the conventional cultures. The cytochrome P450-dependent activity 3,4 -dimethyl-7-ethoxycoumarin-O-dealkylase, was reduced in the LiverBeads when compared to the conventional cultures, although the pattern of conjugation was very similar. In addition, the inducibility of cytochrome P4504A was d emonstrated in LiverBeads. Cultures from cryopreserved cells were more susc eptible to the toxicants tested, and contained less lactate dehydrogenase a nd DNA than the conventional cultures. Overall, in terms of the aspects of drug metabolism measured, the cultures from LiverBeads appeared to be equiv alent to conventional cultures, and superior to cultures from cryopreserved cells.