N-ACETYL CYSTEINE PROVIDES PARTIAL PROTECTION AGAINST TCDD-INDNCED LETHALITY IN FISH EMBRYOS

Cellular oxidative damage is induced by a wide variety of environmenta l factors including UV-irradiation and xenobiotics. 2,3,7,8-Tetrachlor odibenzo-p-dioxin (TCDD), the prototypical xenobiotic, has been shown to induce cellular oxidative damage in the adult rat (Stohs et al., 19 90). The measured endpoints of TCDD-induced oxidative damage in the ra t include: membrane lipid oxidation, DNA damage and protein alteration s. We have tested the hypothesis that TCDD-induced oxidative damage is responsible for the observed lethality after TCDD exposure both in vi tro (a fish cell line, PLHC-1) and in vivo (fish embryos, Oryzias lati pes). To examine the role that cellular oxidative damage plays in TCDD -induced lethality, we tested the ability of an anti-oxidant to provid e protection from TCDD's lethal effects. In the TCDD-treated fish cell s and fish embryos, an anti-oxidant was able to provide partial protec tion from lethality, indicating that TCDD induces cellular oxidative d amage. These data suggest that TCDD-induced cellular oxidative damage plays a role in the toxic manifestation of TCDD in the developing fish embryo. Published by Elsevier Science Ltd