Hydroxylated polychlorinated biphenyls (OH-PCBs) induce vitellogenin through estrogenic activity in primary-cultured hepatocytes of the Xenopus laevis

The results from VTG-assays suggested that an important factor for determining estrogenicity is the positions of the hydroxyl group and chlorine with the highest activity resulting from a para-hydroxyl group. The OH-PCB structures of high rank order in the VTG-assay had no chlorine substituted phenolic ring. Moreover, the meta-chlorine substituted phenolic ring is an important factor in determining estrogenicity. The OH-PCBs with meta-chlorine substituted phenolic ring did not show estrogenicity during VTG-assay.