Aryl hydrocarbon hydroxylase induction in adult rat hepatocytes in primary culture by several chlorinated aromatic hydrocarbons including 2,3,7,8-tetrachlorodibenzo-p-dioxin.

The induction of aryl hydrocarbon hydroxylase (AHH) by Aroclor 1254, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other polychlorinated organic compounds was examined in primary cultures of adult rat hepatocytes isolated by a collagenase perfusion technique. Following exposure of fresh hepatocyte cultures to 1 microgram/ml Aroclor 1254, AHH induction was undetected for 48 hr and then increased dramatically up to 96 hr. Cultures maintained in control medium for either 24, 48, or 72 hr prior to a 24-hr exposure to Aroclor 1254 displayed significant inducible AHH which was sustained to 96 hr. AHH induction was extremely sensitive to two planar polyaromatic hydrocarbons, 2,3,7,8-TCDD and 2,3,7,8-tetrachlorodibenzofuran, and the PCB congener 3,4,3',4'-tetrachlorobiphenyl, but insensitive to 2,6-dichlorodibenzofuran, 2,5,2',5'-tetrachlorobiphenyl, 2,4,5,2',4',5'-hexachlorobiphenyl, and hexachlorobenzene. The induction of AHH activity in primary cultures of adult rat hepatocytes may represent a useful bioassay for screening extracts of foodstuffs, biological fluids, or environmental samples for dioxin-like activity.