Polychlorinated Terphenyls(PCT)の蓄積および代謝(第1報)マウスにおける脂肪組織および肝臓中残留PCTのベンゼン骨格異性体比

抄録

The accumulation of polychlorinated terphenyls (PCTs) and metabolic rates of three types of PCT isomers (polychlorinated ortho-, meta- and para-terphenyls) were investigated for 56 days after a single intraperitoneal administration at 10 mg/mouse. The concentrations of PCTs in adipose tissue increased gradually through the experimental period, while the levels of PCTs in liver peaked at the 1st day after administration and receded rapidly with the passage of times. A significant difference in the composition of accumulated PCTs was found between PCTs in liver and in adipose tissue. The PCTs found in the adipose tissue at the 56 th day after administration were constituted of 14.2% for ortho-, 41.9% for meta- and 43.9% for para-terphenyl. The relative amounts of three terphenyl isomers found in the adipose tissue of mouse were quite similar to those of terphenyl isomers of PCTs accumulated in human adipose tissue. The composition of PCTs in liver changed remarkably with times. The relative amounts of ortho-, meta- and para-terphenyl contained in the PCT residues in the liver at the 1st day were 9.6%, 59.0% and 31.4%, respectively, while those of respective isomers were 7.2%, 79.5% and 13.4% at the 56th day. These results suggest that para-PCTs are more rapidly eliminated from liver than ortho- and meta-PCTs. This finding was confirmed by the fact that the biological half-lives of para-PCTs on both rapid and slow phases were shorter than those of ortho- and meta-PCTs.