Induction of ethoxy-resorufin-O-deethylase activity by halogenated aromatic hydrocarbons and polycyclic aromatic hydrocarbons in primary hepatocytes of the green frog (Rana esculenta).
In this study, we measured the ethoxy-resorufin-O-deethylase (EROD) activity in primary hepatocytes of the common green frog Rana esculenta as a biomarker for cytochrome P4501A induction. We exposed hepatocytes derived from male and female frogs to several halogenated aromatic hydrocarbons, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,3,4,7,8-pentachlorodibenzofuran (PCDF), polychlorinated biphenyls (PCB-126, PCB-118), and polycyclic aromatic hydrocarbons such as benzo[a]pyrene (BaP), chrysene, anthracene, and pyrene. Exposure to PCB-118, anthracene, and pyrene, up to 1 microM, did not induce EROD activity, whereas TCDD and PCDF induced EROD activity maximally. In our primary frog hepatocytes, exposure to chrysene and BaP resulted in median effective concentration values (EC50) in the high nM range (82-1035 nM). Exposure to TCDD, PCDF, and PCB-126 resulted in EC50 values of 0.4 to 8, 0.07 to 0.7, and 3 to 133 nM, respectively, which is in the same range as EC50 values found in primary hepatocytes of birds. Compared to our frog hepatocytes, primary rat hepatocytes seem to be more sensitive to TCDD, chrysene, and BaP.
Rankouhi
Tanja Rouhani
TR
Institute for Risk Assessment Sciences, Utrecht University, P.O. Box 80176, 3508 TD, Utrecht, The Netherlands. t.rouhani@iras.uu.nl
Koomen
Bas
B
Sanderson
J Thomas
JT
Bosveld
Albertus T C
AT
Seinen
Willem
W
van den Berg
Martin
M
D000818:Animals; D002470:Cell Survival; D002478:Cells, Cultured; D019363:Cytochrome P-450 CYP1A1 / Q000096:biosynthesis* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004790:Enzyme Induction / Q000187:drug effects; D005260:Female; D022781:Hepatocytes / Q000187:drug effects* / Q000201:enzymology; D006846:Hydrocarbons, Halogenated / Q000633:toxicity*; D008297:Male; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity*; D011893:Rana esculenta / Q000378:metabolism*
D006846:Hydrocarbons, Halogenated; D011084:Polycyclic Aromatic Hydrocarbons; D019363:Cytochrome P-450 CYP1A1