[Experimental model of urinary bladder tumor in rats for evaluation of chemotherapeutic agents]

The chemotherapeutic agents were evaluated using the experimental urinary bladder tumor rat model induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN). Nine hundred and fourteen male rats received 0.05% BBN in drinking water for 8 weeks, and were divided into 35 groups to follow the regimens of chemotherapeutic agents. Thirty one groups received the agents after BBN treatment, and 4 groups were given the oral agents starting simultaneously with BBN treatment. All rats were killed at 20 weeks and incidence of the urinary bladder was examined histopathologically. The following 13 agents were evaluated; adriamycin (ADM), mitomycin-C (MMC), cyclophosphamide (CPM), 5-fluoro-uracil (5-Fu), N-(2-tetrahydrofuryl)-5-fluorouracil (FT-207), neocarcinostatine (NCS), carbazil quinone (CQ), bleomycin (BLM), vincristine (VCR) and cis-diammine-dichloroplatinum (CDDP) were dosed intraperitoneally, and N-(2-tetrahydrofuryl)-5-fluorouracil (FT-207), 1: 4 mixture of FT-207 and uracil (UFT) and 1-Hexylcarbamoyl-5-fluorouracil (HCFU) were dosed orally. Among these agents, 5-Fu, FT-207, CQ, VCR, CDDP, UFT and HCFU were effective in inhibiting the incidence of urinary bladder tumor induced by BBN. In conclusion, the experimental bladder tumor rat model induced by BBN seems to be useful in evaluating the effective chemotherapeutic agents for a superficial bladder cancer. The importance of the experimental animal model for the evaluation of chemotherapeutic agents is discussed.