THE MICRONUCLEUS ASSAY IN HUMAN EXFOLIATED UROTHELIAL CELLS - EFFECT OF SMOKING

Micronucleated cell rates were examined in exfoliated urothelial cells of 73 healthy donors not occupationally exposed to mutagens or aneuge ns. Micronucleated cell levels averaged 0.54 +/- 0.68% in the entire p opulation: they reached 1.09% in smokers, 0.95% in ex-smokers and 0.24 % in non-smokers. Among variation factors evaluated during this study, only smoking had a significant effect on micronucleated cell rates (P = 0.007) whereas age and sex had no effect (P = 0.101 and P = 0.918). No significant difference was observed between micronucleated cell ra tes of smokers and ex-smokers, suggesting that smoking could generate clones of basal micronucleated cells in urothelial tissues.