Influence of Vitamin A Acetate on Rat Bladder Carcinogenesis

Moon, Woo Chul; Kim, Yung Kyun

Abstract

The influence of vitamin A acetate on the induction of bladder carcinogenesis by N-butyl-N-(4- hydroxybutyl) nitrosamine(BBN) was studied in male Wistar rats. Animals were divided into 4 groups : Group I and II received BBN and/or vitamin A acetate for 12 and 20 weeks. respectively. Group I and II were further divided into 3 subgroups : Subgroup a received BBN only, subgroup b BBN and vitamin A acetate in 100 IU per gram diet and subgroup c BBN and vitamin A acetate in 200 IU per gram diet, respectively. Group E received only vitamin A acetate and Group IV only basal diet. Animals were killed at 20 weeks after first carcinogen exposure and bladder was examined by both light and electron microscopy. At the two dose levels. vitamin A acetate significantly reduced the incidence and extent of carcinoma in Group I, as well as in Group X Vitamin A acetate of lower and higher dosage were nearly same in the inhibitory effect of development of carcinoma. Vitamin A acetate did not reduce the incidence of papilloma, but reduced the extent of papilloma in group I significantly. Vitamin A acetate also reduced the incidence of high grade neoplasm and deeply invasive cancer. Hypervitaminosis A did not develop at both lower and higher dosage of vitamin A acetate. Cancer cells in animals which received both vitamin A acetate and BShl often showed cytolysis, pyknosis and disruption of cellular membrane. The present findings indicate that vitamin A acetate inhibits or delays the development of bladder carcinoma without significant toxicity.