Effects of 2,2′4,4′5,5′-hexachlorobiphenyl (PCB 153) on plasma sex steroids and vitellogenin in rockfish ( Sebastes schlegeli)

Abstract

We examined the estrogenic effect of 2,2′4,4′5,5′-hexachlorobiphenyl (PCB 153) on the rockfish, Sebastes schlegeli. We measured levels of plasma estradiol-17β (E 2) and testosterone (T) by radioimmunoassay (RIA). Plasma concentrations of T and 17α-hydroxyprogesterone in female and male fish injected with PCB 153 using two dosages (0.16 mg/kg body weight. and 0.57 mg/kg) did not differ significantly between sexes or from sham-injected controls of the same sex. Plasma concentrations of E 2 in females injected with PCB 153 (both levels) increased at 12 and 24 h. Concentrations of plasma vitellogenin (VTG) in females increased 72 h after injection with PCB 153 and reached 0.38 and 1.25 mg/mL, respectively. No VTG was detected in males injected with the same dosage. These results suggest that PCB 153 may lead to the production VTG in female rockfish through a synergistic effect with E 2, resulting in indirect disruption of the aromatization process.