Repeated-dose gavage studies on polychlorotrifluoroethylene acids.

C8 polychlorotrifluoroethylene (pCTFE) oligomers accumulate preferentially in the liver during long-term oral exposure and appear to be more hepatotoxic than C6 oligomers. A repeated-dose gavage study was initiated to determine the relative contributions of the corresponding C6 (trimer) and C8 (tetramer) acid metabolites to the toxicity of pCTFE in the male Fischer 344 rat. Test animals were dosed once per week for various time periods up to one year. A depression (p less than 0.05) in mean body weight occurred in the highest dose tetramer acid (2.16 mg/kg) group. An increase in hepatic peroxisomal beta-oxidation activity was found in the 2.16 mg pCTFE tetramer acid/kg dose group at the 3-, 6-, and 9-month sacrifice periods. An increase in relative liver weight was seen at all sacrifice periods in this dose group. Hepatocellular cytomegaly was a common finding in the higher dose tetramer acid groups but not in the trimer-treated rat groups.