EFFECTS OF MONOSODIUM SUCCINATE, DISODIUM SUCCINATE, AND SUCCINIC ACID ON URINARY BLADDER CARCINOGENESIS IN <i>N</i>-BUTYL-<i>N</i>-(4-HYDROXYBUTYL)-NITROSAMINE-INITIATED, UNILATERALLY URETER-LIGATED RATS

Abstract

The effects of monosodium succinate, disodium succinate, and succinic acid on the development of hyperplastic or preneoplastic lesions in the urinary bladder of rats were investigated. These test chemicals were fed to rats after pretreatment for 2 weeks with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) as 0.05% of the drinking water. Rats were subjected to unilateral ureter ligation at week 3 and killed at week 20 of the experiment. In the groups given disodium succinate or sodium citrate (positive control), the incidence of simple hyperplasia was significantly higher than that of the control group given the basal diet alone. The incidence and number per 10cm basal membrane of papillary or nodular hyperplasia of the urinary bladder were higher than the control in the groups given disodium succinate or sodium citrate, although the changes were not statistically significant, probably due to the short administration period of the test chemicals. The results support the significance of the presence of sodium ion and increased urinary pH as promoting factors for urinary bladder carcinogenesis.