Chemical Interactions of Binary Mixture of Selected Polychlorinated Biphenyls in Rat Hepatoma Cell Line (H4IIE)

Abstract : One of the most sensitive biochemical responses to the exposure of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls (PCBs) is the induction of ethoxyresorufin-O-deethylase (EROD). To investigate interactions among TCDD and PCBs, rat hepatoma cells (H4IIE) were exposed to the mixtures of 2,4,5,2',4', 5-hexachlorobiphenyl (PCB#153,fg-microg quantities) and ED50 doses of either TCDD, PCB#77 (3,4,3,4'-tetrachlorobiphenyl), or PCB#126 (3,4,5,3',4'-pentachlorobiphenyl) for 72 hours. EROD activities were measured by spectrofluorometry and dose-related synergistic effects observed in these binary mixtures. At higher concentrations, hover, PCB#153 was an antagonist to TCDD and PCR#126.