Comparative Ability of Various PCBs, PCDFs, and TCDD to Induce Cytochrome P4501A1 and 1A2 Activity Following 4 Weeks of Treatment (Short Communication)

摘要

The toxic equivalency factors (TEF) have been proposed for dibenzo-p-dioxins,dibenzofurans and polychlorinated biphenyls (PCBs). The proposed TEFs, which are presently being evaluated in the authors' laboratory are currently used to estimate the potential health risk associated with exposure to complex mixtures containing these chemicals. Hepatic cytochrome P-450 1A1 and 1A2 activities were determined for all chemicals tested and compared to those from TCDD treated mice. These initial studies indicate that the interim TEFs for the dibenzofurans adequately predict the relative induction potency for these compounds. However, the TEFs proposed for the 'dioxin-like' PCBs overestimate the potency of these compounds by factors of 10-10,000. The present study indicates that more experimental data is required before TEFs for PCBs are used in regulatory decision making. (Copyright (c) 1993 by the Society of Toxicology.)