Biopsy material of urine bladder was researched in 159 men without clinical symptoms of urinary bladder deseases, which were perfomed trans-bladded adenomectomy for benign hyperplasia of prostate, and 5 women with a chronic cystitis. It is established that in a group of patients, living at the territory polluted by 137Cs (5–30) and (0,5–5) km2, and with a specific activity in urine Cs (6.47±1.43) and (1.23±1.00) accordingly, dysplasia urothelium was detected in 97 and 83 % and the numerous cancer zones — in situ with neoplastic changes in 73 and 64 %. The overexpression of p38 MAPK and subunit NF-kB — p65 and p50 in urothelial cells was detected, that is evidence of an important role of the oxidative stress development in a pathogenesis of chronic atipic cystitis (“Chernobyl cystitis”), which develops as a result of chronic long action of ionizing radiation in persons living at the territories polluted by 137Cs radionucleotides.
