TCDD, endrin and lindane induced oxidative stress in fetal and placental tissues of C57BL/6J and DBA/2J mice.

The abilities of TCDD, endrin and lindane to induce oxidative stress in fetal and placental tissues have been studied after the oral administration of these xenobiotics to pregnant C57BL/6J and DBA/2J mice. Production of superoxide anion, lipid peroxidation and DNA-single strand breaks (SSB) was determined in live fetal and placental tissues 48 hr after administration of single teratogenic doses of the compounds on day 12 of gestation. Oxidative stress and its biomarkers were also determined in livers of day 18 fetuses after administration on day 12 of gestation. TCDD given at doses of 30 and 60 micrograms/kg body weight to the C57BL/6J and DBA/2J mice, respectively, produced increases of 1.3-2.7-fold in superoxide anion production, 1.6-1.9-fold in lipid peroxidation and 2.1-4.4-fold in DNA-SSB. Endrin, given at a dose of 4.5 mg/kg body weight to C57BL/6J and DBA/2J mice, produced increases of 1.3-2.8-fold in superoxide production, 1.4-1.8-fold in lipid peroxidation and 1.4-4.7-fold in DNA-SSB. Lindane when given at a dose of 30 mg/kg body weight to C57BL/6J and DBA/2J mice produced increases of 1.6-3.0-fold in superoxide production, 1.3-2.1-fold in lipid peroxidation and 1.4-5.0-fold in DNA-SSB. The results suggest that superoxide production, lipid peroxidation and DNA-SSB in fetal and placental tissues may participate in the fetotoxic effects of TCDD and other polyhalogenated cyclic hydrocarbons, and that TCDD-induced oxidative damage in fetal and placental tissues is mediated at least in part by the Ah-receptor. The results also indicate that TCDD as an inducer of oxidative tissue damage in the embryos and placentas is approximately 150 and 1000 times more potent than endrin and lindane, respectively, in C57BL/6J mice, and 75 and 500 times more potent than endrin and lindane, respectively, in the DBA/2J mouse strain.