EVALUATION OF MICRONUCLEI IN EXFOLIATED UROTHELIAL CELLS AND URINARY THIOETHER EXCRETION OF SMOKERS

Mutagens are present in large quantities in the urine of cigarette smo kers, thus, their urothelial cells may represent a possible target for absorbed and excreted mutagens. Our aim is to validate the micronucle us (MN) test in exfoliated urothelial cells obtained from urine sample s of cigarette smokers. The urinary thioether (UT) test is also carrie d out on the same individuals in order to find out whether there is an y correlation between these two end-points. The mean (+/-SE) MN freque ncy and UT determination is 1.93 (+/-0.11)% and 9.71 (+/-1.61) mmol SH /mol creatinine for 23 smokers, and 0.66 (+/-0.05)% and 4.20 (+/-0.56) mmol SH/mol creatinine for 20 nonsmokers. Our results show a higher f requency of micronucleated cells (p < 0.001) and higher excretion of U Ts (p < 0.05) in smokers as compared to nonsmokers. Concentrations of UTs and MN frequencies increased with tobacco consumption. The MN freq uencies showed only a marginal increase, not significant (p > 0.05), a fter passive smoking compared to nonsmoking values. There was no signi ficant correlation between MN frequencies and UTs, either in smokers ( r = 0.164, p > 0.05) or in nonsmokers (r = -0.018, p > 0.05). Our data demonstrate tobacco-induced chromosome damage in bladder tissue consi stent with increased risk of cancer at this site among smokers.