Induction of single-strand breaks and interstrand cross-links in liver DNA after the administration of 2-acetylaminofluorene andtrans-4-acetylaminostilbene to rats
✍ Scribed by Ruthsatz, M. ;Neumann, H.-G.
- Publisher
- John Wiley and Sons
- Year
- 1987
- Tongue
- English
- Weight
- 405 KB
- Volume
- 2
- Category
- Article
- ISSN
- 0887-2082
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✦ Synopsis
2-Acetylaminofluorene (AAF) or trans-4-acetylaminostilbene (AAS) was orally or intraperitoneally administered to female Wistar rats. DNA from liver cells was analyzed for single-strand breaks by the alkaline elution assay. Only borderline effects were observed with doses (100 pmol/kg) used in animal carcinogenesis experiments. Even high doses of AAF (1,000 pmol/kg) were not effective. Methyl methanesulfonate (MMS) in vivo and gamma irradiation in vitro were shown to produce dose-dependent DNA single-strand breaks (positive control). Only a marginal effect was obtained with 100 pmollkg MMS. The elution rate of DNA was increased by a factor of 34 in liver cells in vitro with 400 rad of gamma irradiation. Only a fraction of this rate could be demonstrated immediately after irradiation in vivo, and no lesions were found two hours later. This strongly indicates the rapid repair of single-strand breaks. Additional experiments showed that AAS, a nonhepatocarcinogen, produced more interstrand cross-links in the rat liver DNA than did AAF. KEY WORDS: Single-strand breaks i n vivo, 2-acetylaminofluorene, trans-4-acetylaminostilbene Manuscript