Effect of 1-hexylcarbamoyl-5-fluorouracil on development of rat urinary bladder tumor induced by N-butyl-N-(4-hydroxybutyl)nitrosamine.

The present study was conducted to examine the effect of 1-hexylcarbamoyl-5-fluorouracil (HCFU) on the development of urinary bladder tumors induced by N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in rats. One hundred twenty male Fischer 344 rats were divided into 6 groups. Sixty rats (groups 1, 2 and 3) were given 0.05% BBN in drinking water for the initial 8 weeks of the experiment and another 60 rats (groups 4, 5 and 6) served as controls. HCFU mixed in the powder diet was administered at daily doses of 100 mg per kg of body weight. Group 2 received HCFU throughout and group 3 after BBN administration for 8 weeks. All animals were sacrificed at 20 weeks from the beginning of the experiment and examined histopathologically. In groups 1, 2 and 3, urinary bladder tumors developed in 13 of 18, 0 of 20, and 4 of 19, respectively. Incidences of tumors in the 2 groups treated with HCFU were significantly lower than that of group 1 treated with BBN alone. These results indicated that HCFU was effective in suppressing the incidence of bladder tumor.