[Urinary bladder carcinogenicity of BBN in beige mice (Chediak-Higashi disease model)]

To study the effect of natural killer (NK) activity on chemical carcinogenesis in urinary bladder cancer, beige mice (NK deficient mice) and C57BL/6 mice (NK normal mice) received N-bytyl-(4-hydroxybutyl) nitrosamine (BBN) in drinking-water. The effect was evaluated by measuring the incidence of early neoplastic change in the urinary bladder. OK-432, a biological response modifier, was administered in drinking-water and its effect on carcinogenesis was evaluated. The beige and C57BL/6 mice were divided into two groups. Group A, C57BL/6 mice and group C, beige mice received 0.1% BBN in their drinking-water. Group B, C57BL/6 mice, and group D, beige mice, received 0.1% BBN and OK-432 (5KE/1000 ml) in their drinking-water for 4 weeks. The mice were sacrificed at 12, 14, 16, 18 and 24 weeks after BBN administration and the urinary bladder was examined histologically by light and scanning electron microscopy. In the light microscopic findings, all groups had no neoplastic change at 12, 14 and 16 weeks, although at 18 and 24 weeks, neoplastic changes were observed. The incidence at 18 weeks was 0/10 in in group B, 2/5 in group C and 3/6 in group D. (p less than 0.01 between beige and C57BL/6 mice at 18 weeks). In the scanning electron microscopic findings, cells with a cobble stone appearance, pleomorphic microvilli and short uniform microvilli on luminal surfaces are observed during carcinogenesis in urinary bladder.(ABSTRACT TRUNCATED AT 250 WORDS)