Mechanisms of Cellular Membrane Effects of TCDD, Selected Perfluorinated Acids and Polyhalogenated Aromatic Hydrocarbons

The first six months of the contract have been devoted to examining the effects of perfluorinated acids and polyhalogenated aromatic hydrocarbons on the colony-forming ability of L5178Y cells. Two sub clones of this cell line have been utilized. One sub clone is designated L5178Y TK. The two cell lines differ markedly in their growth characteristics. L5178Y TK- cells tend to associate in clumps of cells and are grown in a shaker incubator to produce better cell suspensions. L5178Y TK cells grow as a single cell suspension without agitation. The toxic response of both cell lines after treatment with the perfluorinated acids perfluoro-n-decanoic acid was measured. In summary, the results for the perfluorinated acids with chain length of 9 or 10 indicate that there is some dissociation of colony growth from suspension growth. Medium type does not affect the toxicity. This would imply that these perfluorinated acids are producing toxicity through a membrane interaction. The dissociation appears to occur in the TK cells at concentrations approximately 20 higher than those previously reported. aw