| Research Abstract |
(1). Species difference in metabolism of PCB
Tissue distribution of hydroxylated and methylsulfonyl PCB were largely different among rats, mice, guinea pigs and hamsters after exposure to 2,4,5,2',5'-pentaCB (CB101) and 2,3,4,2',3',6'-hexaCB (CB132). Hamster blood strongly retained a catechol metabolite from CB132. Gunn rats, hereditarily UGT1s deficient, highly produced catechol metabolites derived from CB110 and CB149 after exposure to Kanechlor 500.
(2). Metabolism of polybrominated biphenyl and enzyme induction
3'-MeSO_2-2,4,2',5'-tetraBrB, a metabolite of 2,4,2',5'-tetraBrB, was found to be a potent inducer of CYP2B1/2 in rats. Unlike MeSO_2-PCBs, this metabolite showed no reduction of thyroid hormone (T4) level in rat serum.
(3). Halogenated pollutants in whale meat and its biological effects.
Several brominated compounds as well as chlorinated ones (PCB, DDTs and chlordanes) were detected in whale products. Exposure of mice to the organohalogen contaminants in blubber products resulted in changes of some biochemical parameters (GPT, amylase and T4) in serum. Also, these pollutants were exposed to cultured rat embryos during organogenesis, where the tetratogenicity was observed in a dose-dependent manner.
(4). MeSO_2-PCBs in human liver
Human liver was analyzed for MeSO_2-PCBs by negative CI/GC/MS technique. A major component was 5'-MeSO_2-2,3,4,2',3',6'-hexaCB (about 60% of total MeSO_2-PCBs), followed by 3- or 4-MeSO_2 metabolites derived from CB87, CB101 and CB149.
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