Effects of InUtero Exposure to 4-hydroxy-2,3,30,40, 5-pentachlorobiphenyl (4-OH-CB107) on Developmental Landmarks, Steroid Hormone Levels, and Female Estrous Cyclicity in Rats

Previous studies have revealed that one of the major metabolites of PCBs detected in human blood, 4-OH-2,3,30,40,5-pentaCB (4-OH-CB107), accumulated in fetal liver, brain, and plasma and reduced maternal and fetal thyroid hormone levels after prenatal exposure to pregnant rats from gestational days (GD) 10–16. In the present study, the effects of 4-OH-CB-107 on developmental land-marks, steroid hormone levels, and estrous cyclicity of rat offspring after in utero exposure to 4-OH-CB107 was investigated. Pregnant rats were exposed to 0, 0.5, and 5.0 mg 4-OH-CB107 per kg bw from GD 10 to GD 16. Another group of rats was exposed to Aroclor 1254 (25 mg/kg bw) to study the differences between effects caused by parent PCB congeners and the 4-OH-CB107 alone. A significant, dose-dependent prolongation of the estrous cycle was observed in 75 % and 82 % of female offspring exposed to 0.5 and 5.0 mg 4-OH-PCB107, respectively, compared to 64 % of Aroclor 125