Promoting effect of unilateral nephrectomy on urinary bladder carcinogenesis in rats

The effect of unilateral nephrectomy on the growth of bladder tumors was investigated in male F344 rats treated with 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine(BBN) for 6 weeks by means of macroscopical and microscopical examinations. Unilateral nephrectomy 4 weeks after the initiation of BBN administration significantly increased both the number and the volume of visible tumors per rat as compared with the sham-operated group. Histological examination also revealed that the numbers of papillonodular hyperplasia and cancer per basement membrane were significantly increased by unilateral nephrectomy. The results imply a growth-enhancing effect of unilateral nephrectomy on carcinogenesis of the rat bladder.