Effect of cyclophosphamide on rat urinary bladder epithelium treated wtih N-butyl-N-(4-hydroxybutyl)nitrosamine.

The effect of cyclophosphamide (CP) on the urinary bladder epithelium of rats treated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) was examined histologically to detect preneoplastic papillary or nodular hyperplasia. The urinary bladder epithelium of rats injected intraperitoneally with 40 or 80 mg/kg body weight of CP after treatment with 0.025% BBN for 2 weeks showed extensive epithelial erosion and then simple, or papillary or nodular hyperplasia, but this soon almost disappeared. In contrast, rats given BBN alone showed papillary or nodular hyperplasia later. These findings indicate that epithelial damage by CP inhibited the early neoplastic process of BBN.