Study on influence of cigarette smoking on the mutagenicity of urine. I. Influence of cigarette smoking on the mutagenicity of urine in healthy smokers and bladder cancer patients

We studied the mutagenicity of urine of healthy smokers and smokers with bladder tumors by the Ames test. The 41 healthy smokers studied showed a significant increase in urinary mutagenic activity compared to the 24 passive smokers and the 22 non-smokers, but there was no significant difference between the passive smokers and non-smokers. In the 5 healthy subjects, the urinary mutagenic activity increased in accordance with the increase of tobacco consumption. In the 32 healthy subjects and 22 smokers with bladder tumors, the time-course changes of the mutagenicity of urine after smoking were investigated by testing the urine every 2 hours. In the healthy subjects, urinary mutagenic activity was increased up to 4 hours after cigarette smoking and decreased to the level noted before smoking after the 6th hour. By contrast, in the 22 smokers with bladder tumors, the urinary mutagenic activity remained high even after the 6th hour, and only decreased to the level seen before smoking after the 8th hour. The influence of smoking on the mutagenicity of urine tended to protract in smokers with bladder tumors in comparison to healthy smokers. There was no correlation between urinary mutagenic activity and tumor status and recurrence rate of the bladder tumors.