[Changes in the urinary bladders of rats during experimental carcinogenesis]

Rats receiving with drinking water a 0.4% solution of a-butyl-N-butanol-nitrosamine developed by 4 months transitional cell papillomas and by 10 months transitional cell carcinomas in their urinary bladders. Histochemical examinations of the transitional epithelium in the course of malignization revealed a gradual decrease in the activity of nonspecific alkaline phosphatase and increased activity of monoaminoxidase and beta-glucuronidase. A significantly increased activity of nonspecific acid phosphatase was observed in areas of squamous cell metaplasia.