Quantitative and statistical analysis of differences in sensitivity between Long–Evans and Han/Wistar rats following long-term exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin
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- 作者：Salomon S ; Nicholas Fletcher ; Dietrich von Rosen ; Fereshteh Kalantari ; Matti Viluksela ; Jouni T. Tuomisto ; Jouko Tuomisto ; Agneta Falk-Filipsson ; Helen Hå ; kansson
- 关键词：Strain variation ; Strain sensitivity ; Benchmark dose ; BMD ; TCDD ; Dose-response
- 刊名：Regulatory Toxicology and Pharmacology
- 出版年：2010
- 出版时间：July-August 2010
- 年：2010
- 卷：57
- 期：2-3
- 页码：136-145
- 全文大小：775 K
文摘
In this study, differences in sensitivity between Long–Evans (L–E; dioxin sensitive) and Han/Wistar (H/W; dioxin resistant) rats following long-term exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were statistically and quantitatively investigated. Sensitivity differences were analyzed by comparing benchmark doses (BMDs) for the two strains considering a number of toxicological endpoints including data on body and organ weights, hepatic foci, hepatic CYP1A1 induction, as well as tissue retinoid levels. Dose–response relationships for L–E and H/W rats, described by the Hill function, were assumed to be parallel, which was supported according to statistical analysis. It was concluded that L–E and H/W rats differed statistically in their response to TCDD treatment for most of the parameters investigated. Differences between the strains were most pronounced for hepatic foci; L–E rats were approximately 20–40 times more sensitive than H/W rats. For body and organ weight parameters, L–E rats were approximately 10–20 times more sensitive than H/W rats. For retinoid parameters and hepatic CYP1A1 induction, estimated differences between the strains were generally about 5-fold, and associated with a low uncertainty. In conclusion, the present study employs a dose–response modeling approach suitable for statistical evaluation of strain and species differences in sensitivity to chemical exposure. The study demonstrates quantitatively the differences in sensitivity between the L–E and H/W rat strains following long-term TCDD exposure.