Ability of polycyclic aromatic hydrocarbons to induce 7-ethoxyresorufin-o-deethylase activity in a trout liver cell line.
Along with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 24 unsubstituted polycyclic aromatic hydrocarbons (PAHs) were evaluated for their ability to induce 7-ethoxyresorufin-o-deethylase (EROD) activity in the rainbow trout liver cell line RTL-W1. When the duration and cell density of exposure were increased, the EC(50) for EROD induction was relatively constant for TCDD, but increased for PAHs. Regardless of exposure conditions, EROD activity was not induced by 9 PAHs: naphthalene, phenanthrene, anthracene, pyrene, perylene, acenaphthylene, acenaphthene, fluorene, and fluoranthene. Two PAHs, benzo[g,h,i]perylene and coronene, induced EROD activity inconsistently. The remaining 13 PAHs consistently induced EROD activity. The EC(50)s for induction exhibited approximately a 110-fold range. The order of potency, from most to least potent, was benzo[k]fluoranthene, dibenzo[a,i]pyrene, dibenzo [a,h]anthracene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, benzo [b]fluoranthene, pentacene, benzo[b]anthracene, benzo[b] fluorene, chrysene, benzo[a]anthracene, benzo[e]pyrene, and triphenylene. When the induction potency was expressed relative to TCDD, the toxic equivalency factors (TEFs) ranged from 0.001 to 0.000 01. When expressed relative to benzo[a]pyrene, the TEFs ranged from 3.44 to 0. 03.
Bols
N C
NC
Department of Biology, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada. ncbols@sciborg.uwaterloo.ca
Schirmer
K
K
Joyce
E M
EM
Dixon
D G
DG
Greenberg
B M
BM
Whyte
J J
JJ
D000818:Animals; D002460:Cell Line; D019363:Cytochrome P-450 CYP1A1 / Q000187:drug effects / Q000378:metabolism*; D004790:Enzyme Induction; D006841:Hydrocarbons, Aromatic / Q000494:pharmacology* / Q000633:toxicity; D008099:Liver / Q000201:enzymology*; D017686:Oncorhynchus mykiss / Q000502:physiology*; D011083:Polycyclic Compounds / Q000494:pharmacology* / Q000633:toxicity; D012016:Reference Values; D014874:Water Pollutants, Chemical / Q000494:pharmacology* / Q000633:toxicity
D006841:Hydrocarbons, Aromatic; D011083:Polycyclic Compounds; D014874:Water Pollutants, Chemical; D019363:Cytochrome P-450 CYP1A1