Influences of aging and sex on renal pelvic carcinogenesis by N-butyl-N-(4-hydroxybutyl)nitrosamine in NON/Shi mice.

Influences of aging and sex on renal pelvic carcinogenesis induced by N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) were examined in 6-, 15 -and 45-week-old male and female NON/Shi mice. Histopathological examination revealed an age-related shortening of induction time for renal pelvic carcinomas in males, although actual incidences did not increase. The histological patterns of carcinomas induced in both renal pelvis and urinary bladder demonstrated male mice to be more prone to develop transitional cell carcinomas, while squamous cell carcinomas were more likely to arise in females. Moreover, the sex factor appeared to influence the progression of both renal pelvic and urinary bladder carcinomas.