MP11 Advances in Bioaccumulation Assessment
Monday, 14 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(DYE-1117-806668) Use of fish hepatocyte suspensions to estimate bioconcentration.

Dyer, S¹, Bernhard, M¹, ¹ The Procter and Gamble Company, Cincinnati, Ohio, USA

ABSTRACT- The rate of biotransformation is a dominant factor in determining the extent to which chemicals may bioconcentrate. Biotransformation can be measured in vitro via studies with cellular or subcellular preparations. An advantage of in vitro systems is that they are relatively inexpensive compared to in vivo tests. We have developed a plated cell hepatocyte test that has allowed the determination of parent molecule uptake and subsequent loss from the cell due to metabolism via a first-order rate formation and decay model. We term the ratio of the uptake and loss via metabolism as the BCFcell. BCFcell data have been developed for several radiolabeled chemicals. Future tests, however, will likely require cold-analytical methods. To meet this need, we have developed a suspension-based system that allows greater flexibility in exposure regimes. For instance, numbers of cells per volume, total volume, regulation of head-space for volatile chemicals are among the many regimes that can be altered with suspensions. Direct comparisons of plated vs. suspension-based rates and BCFcell data for linear alkyl benzene sulfonate and alcohol ethoxylate surfactants will be presented.

Key words: BCFcell, kinetics, uptake rate, loss rate