Timing Effects of Uracil-induced Urolithiasis on Amplification of Second-stage Promotion in Rat Bladder Carcinogenesis
| Autor: | Tomoyuki Shirai, Ryohei Hasegawa, Shoji Shoji, Masashi Sano, Masaaki Shibata |
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| Rok vydání: | 1991 |
| Předmět: |
Male
Cancer Research medicine.medical_specialty Urinary Bladder Amplification medicine.disease_cause Drug Administration Schedule Article Lesion chemistry.chemical_compound Internal medicine Tumor promotion Animals Medicine Uracil Carcinogen Urinary bladder DNA synthesis business.industry Body Weight Sodium Rats Inbred F344 Rats Uracil – Rat Bicarbonates Sodium Bicarbonate Endocrinology medicine.anatomical_structure Urinary Bladder Neoplasms Oncology chemistry Nitrosamine Carcinogens Cancer research Urinary Calculi Butylhydroxybutylnitrosamine medicine.symptom business Carcinogenesis |
| Zdroj: | Japanese Journal of Cancer Research : Gann |
| ISSN: | 0910-5050 |
| DOI: | 10.1111/j.1349-7006.1991.tb01760.x |
| Popis: | The post‐initiation enhancing activities of the non‐genotoxic agent NaHCO3 and the genotoxic agent N‐ethyl‐]N‐(4‐hydroxybuty])nitrosainine (EHBN) in combination with uracil‐induced urolithiasis were investigated in a rat bladder carcinogenesis model. Animals were treated with 0.05%N‐butyl‐N‐(4‐hydroxybutyl)nitrosamine (BBN) for 4 weeks, and then 3% uracil was given for 3 weeks in the early (weeks 4‐7), middle (weeks 8 11) or late (weeks 12–15) post‐initiation phase. In addition, administration of 3% NaHCO3, 20 ppm EHBN or no chemical supplement was performed for the 13 weeks when the rats were not receiving BBN or uracil. NaHCO3 in sequential combination with early and middle stages uracil treatment strongly enhanced tumorigenesis in the urinary bladder, while EHBN treatment amplified lesion development at the middle stage only of uracil treatment. DNA synthesis and associated epithelial surface alterations observed by scanning electron microscopy tended to be increased in the NaHCO3 and EHBN groups without BBN initiation, independently of uracil treatment timing. The present results demonstrated that uracil‐induced urolithiasis during the middle post‐initiation phase is highly active in enhancing bladder tumor development under the influence of a promoter or carcinogen. |
| Databáze: | OpenAIRE |
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