Inhibition of dye transfer in rat liver WB cell culture by polychlorinated biphenyls.

In the present investigation the scrape loading/dye transfer assay and microinjection technique are used in order to investigate inhibition of cell-cell communication induced by different polychlorinated biphenyl (PCB) congeners. In these in vitro assays, inhibition of intercellular communication is directly measured as decreased transfer of a fluorescent dye (Lucifer Yellow CH) from donor cells loaded with the dye to surrounding recipient cells. The results show that substitution in the ortho position from the carbon bridge is essential and at least one chloro substituent in ortho position is necessary for the ability to inhibit intercellular communication. The results also suggest that an increase in the number of ortho substituted chlorine atoms in the PCB molecule enhances the ability to inhibit intercellular communication. On the other hand, the total number of substitutions may not be crucial for the ability to inhibit intercellular communication. Our results suggest that PCB-induced down-regulation of intercellular communication is a result of a specific mechanism and not due to unspecific membrane perturbation.