Influence of prior freezing on arylamine acetylation by human liver preparations.
Human liver tissue is an important resource for use in xenobiotic metabolism studies. Because of the scarcity of human livers, studies are frequently conducted with subcellular preparations from previously frozen material. The influence of prior freezing on arylamine acetylation with human S-9 was studied and differences were found between S-9 preparations derived from fresh liver and from stored frozen liver. Specifically, the capacity for formation of diacetylated benzidine was lost as a result of tissue freezing, and the rate and extent of monoacetylation appeared to be reduced also, though not as dramatically. These results demonstrate that freezing of human tissue prior to conducting metabolism studies with arylamines may alter metabolite profiles and indicate that, for reliable data, before using frozen human tissue in metabolism studies with arylamines one should check first for this possibility.
Green
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SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025, USA.
Gordon
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Peters
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Tyson
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CA