HEXACHLOROBENZENE (HCB) DEPOSITION IN MATERNAL AND FETAL TISSUES OF RAT AND MOUSE .1. CHEMICAL QUANTIFICATION OF HCB IN TISSUES

CD-1 mice received a single treatment of hexachlorobenzene (HCB) on Day 11 or 16 of gestation or daily treatments on Days 6-11 or 6-16 of gestation at levels of 10, 50, or 100 mg/kg. CD rats received daily treatments of 10 or 50 mg/kg HCB on Days 6-12 or 12-16 of gestation. Animals were sacrificed 24 hr after last dose and maternal and fetal tissues were assayed for HCB content. Rat and mouse fetuses and placentas showed a dose-dependent concentration of HCB, and generally, the fetuses had a lower concentration than their respective placentas. Multiple low doses of HCB resulted in higher concentrations of HCB in mouse maternal and fetal tissues than single doses of equivalent total dose. Late gestational rats received fewer doses of HCB than midgestational rats, yet their fetuses and placentas had significantly higher concentrations of HCB suggesting a gestational effect. Resorptions had higher average HCB concentrations than their living counterparts at all dose regimens. © 1979.