Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1992-9-1
pubmed:abstractText
The metabolism of testosterone and benzo(a)pyrene (BaP) which is mediated by diverse enzymes was determined in cryopreserved rat liver parenchymal cells and compared with that found in freshly isolated cells. In addition, the activities of single xenobiotic-metabolizing enzymes were measured by using specific substrates. The cytochrome P450 (P450)-mediated total metabolic conversion of testosterone was reduced to 55% in cryopreserved cells. The metabolite profile, i.e. the formation of single metabolites compared with total metabolic conversion, was however unchanged when compared with freshly isolated cells. A concomitant reduction in the activities of the involved P450 isoenzymes can therefore be postulated. The amount of detected phase I-metabolites of BaP was unaffected by the cryopreservation method. The formation of phase II-metabolites and total metabolic conversion of BaP in cryopreserved cells was however reduced to about 50-60%. The reduced glutathione S-transferase and more obviously phenol sulfotransferase activities measured in cryopreserved cells, may explain the impaired conjugation of BaP. The ratio between phase I- and phase II-metabolites was thus changed by cryopreservation. Density separation on Percoll yielded cryopreserved cells with a viability and metabolic capacity not measurably different from freshly isolated cells. To this extent, cryopreserved, Percoll-purified liver parenchymal cells are a useful in vitro system for drug metabolism studies. However due to the extensive loss in cell number during this procedure (recovery = 22% of freshly isolated cells) the application of this system is limited.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2952
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
309-15
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Characterization of cryopreserved rat liver parenchymal cells by metabolism of diagnostic substrates and activities of related enzymes.
pubmed:affiliation
Institute of Toxicology, University of Mainz, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't