Effects of foreign bodies on development of urinary bladder tumors in rats treated with N-butyl-N-(4-hydroxybutyl) nitrosamine.

The effects of chronic mechanical stimulation induced by glass balls or paraffin balls on precursor lesions of the urinary bladder of male Wistar strain rats induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) in the drinking water were studied. When foreign bodies were present in the bladder, proliferative lesions of the urinary bladder epithelium were found even without administration of carcinogen. When the foreign bodies were implanted into the urinary bladder and then rats were given BBN in the drinking water for the first 4 weeks of the experimental period, a high incidence of tumors of the urinary bladder was observed. The incidence of tumors induced by BBN was increased by the presence of glass balls or paraffin balls in the urinary bladder. These results clearly show that foreign bodies in the urinary bladder have a significant effect in promoting carcinogenesis of the urinary bladder in rats. [ABSTRACT FROM AUTHOR]