Details

Autor(en) / Beteiligte

• Golor, Georg
• Koch, Elisabeth
• Schulz-Schalge, Thomas
• Yamashita, Keisuke
• Wiesmüller, Thomas
• Körner, Wolfgang
• Hagenmaier, Hanspaul
• Neubert, Diether
• Birnbaum, LS
• Giesy, JP
• Fiedler, H
• Denison, M
• Hutzinger, O (eds)
• Fingerhut, M
• Ahlborg, UG
• Clement, RE

Titel

Concentration-effect analyses with TCDD, H7CDD and OCDD in female Wistar rats

Ist Teil von

• Chemosphere, 1992, Vol.25 (7), p.923-930

Ort / Verlag

Oxford: Elsevier Ltd

Erscheinungsjahr

1992

Quelle

Elsevier Journal Backfiles on ScienceDirect (DFG Nationallizenzen)

Beschreibungen/Notizen

• The induction of hepatic monooxygenases in female Wistar rats was measured after repeated subcutaneous injections of 1,2,3,4,6,7,8-heptachlorodibenzo- p-dioxin (H7CDD) and octachlorodibenzo- p-dioxin (OCDD), and the potency of these congeners to induce this hepatic enzyme activity was compared with that of TCDD. The biological effects were correlated with tissue concentrations of the congeners, and concentration-effect curves were established, allowing the assessment of a NOEC (no-observed-effect-concentration). A clear induction of ethoxyresorufin O-deethylase (EROD) activity in liver microsomes was observed after treatment with highly purified OCDD, but the inducing potency of this congener was clearly more than 10 times lower than that of H7CDD. When compared with TCDD our data suggest that the potency of H7CDD at the NOEL is 1 700 of that of TCDD, whereas OCDD, at this biological level, seems to have an inducing potency of less than 1 10,000 of that of TCDD. Since it was found that the concentration-effect curves for the congeners do not run completely parallel, lower potency factors (when compared with TCDD) are calculated, namely: 100 for H7CDD, and 2,000 for OCDD. Our results explain some of the apparent discrepancies found in the literature.