F344/Shi rats bearing type b catalase-1 locus are sensitive to sodium L-ascorbate promotion of two-stage urinary bladder carcinogenesis
✍ Scribed by Satoru Mori; Takashi Murai; Motoko Hosono; Hirofumi Yamashita; Tadao Oohara; Susumu Makino; Masami Doteuchi; Shoji Fukushima
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 25 KB
- Volume
- 18
- Category
- Article
- ISSN
- 0270-3211
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✦ Synopsis
Our previous data showed that F344/DuCrj and LEW/Crj rat strains bearing the type a catalase-1 locus (CS1 a ) are sensitive to the promoting activity of sodium L-ascorbate (Na-AsA) in 2-stage urinary bladder carcinogenesis, whereas ODS/Shi and WS/ Shi rat strains bearing the type b catalase-1 locus (CS1 b ) are resistant. In present study, we investigated the susceptibility of F344/Shi rats also bearing the CS1 to the Na-AsA-promoting effects on bladder tumor development. Male rats, 6 weeks old, were given 0.05% N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) in their drinking water for 4 weeks, then fed either basal diet supplemented with 5% Na-AsA or no chemicals for 32 weeks. The rats given BBN alone had a few small carcinomas in the urinary bladder. In contrast, animals administered BBN-Na-AsA had many large carcinomas. Administration of Na-AsA was associated with significant elevation of urinary pH and L-ascorbic acid. The results indicate that F344/Shi rats are sensitive to the promoting effects of Na-AsA on 2-stage urinary bladder carcinogenesis, and thus that the CS1 locus may not influence susceptibility to promotion.