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ACCUMULATION OF PBDE-47 IN PRIMARY CULTURES OF RAT NEOCORTICAL CELLS.
Citation:
Mundy, W R., T Freudenrich, K M. Crofton, AND M J. DeVito. ACCUMULATION OF PBDE-47 IN PRIMARY CULTURES OF RAT NEOCORTICAL CELLS. Presented at Society of Toxicology, New Orleans, LA, March 06 - 10, 2005.
Description:
A number of recent studies have examined the neurotoxic actions of PBDEs using in vitro cell culture models. However, there is little data reporting the final concentration of PBDEs in cells after in vitro exposure to these compounds. To address this issue, the present study examined the concentration- and time-dependent accumulation of 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47) in primary cultures of rat neocortex. Mixed cultures of neuronal and glial cells were prepared from the neocortex of newborn rats and grown for 7 days in vitro. The cells were then exposed to freshly prepared serum-free culture media containing 14C-PBDE-47. Radiolabel associated with the cells or remaining in the media was determined by liquid scintillation spectrometry. Exposure to 0.01 - 3.0 M PBDE-47 for 60 min resulted in a concentration-dependent accumulation in cells. At each concentration approximately 15% of the applied PBDE-47 was associated with the cells, resulting in a 100-fold magnification of the applied concentration (e.g., a 60 min exposure to 1 M resulted in an approximate 100 M concentration in the cells); 55% of the PBDE remained in the media and 30% was associated with the plastic culture dish. Exposure to 1 M PBDE-47 resulted in a linear increase in PBDE-47 in cells with time for the first 60 min, which began to saturate at 120 min. Addition of serum proteins to the media decreased accumulation; at 10% serum in the media only 3% of the applied PBDE-47 was associated with the cells and 96% remained in the media after 60 min. The total volume of exposure also influenced accumulation of PBDE-47. Doubling the volume of serum-free exposure media (from 2 ml to 4 ml) while leaving the concentration constant (1 M) resulted in an 1.5-fold increase in PBDE concentration in the cells. These data show that a number of factors, including duration of exposure, volume of exposure, and concentration of serum proteins in the media, can influence the accumulation of PBDE in cells in vitro. For this highly lipophilic compound, use of media concentration underestimates tissue concentration by up to 2 orders of magnitude. Thus, accurate information on the tissue concentration for in vitro experiments should be determined empirically. (This is an abstract of a proposed presentation and does not necessarily reflect EPA policy).