Fig. 8.

4-52 and six dihydroxylated metabolites, including three dechlorinated metabolites X1-52 X2-52,and X3-52 were detected in (A) serum, (B) brain, (C) liver, and (D) lung of male rats exposed for 28 days to 4-52 via polymeric implants containing 0 (sham), 1, 5, or 10% of 4-52. (E) illustrated the possible metabolic pathway of 4-52. Data are the mean ± standard deviation (n = 8). X indicates a dihydroxylated trichlorobiphenyl metabolite; Y indicates a dihydroxylated tetrachlorobiphenyl metabolite. ND: not detected. SULT: sulfotransferase. UGT: UDP-glucuronosyltransferase. COMT: Catechol-O-methyltransferase The y-axis is in a log scale to facilitate a comparison between tissue levels. The concentrations are normalized by tissue wet weight (ng/g).