Long-term feeding study in C17 mice administered saccharin coated betel nut and 1,4-dinitrosopiperazine in combination.

The observations on the effect of 3 agents--1,4-dinitrosopiperazine, betel nut and saccharin fed to C17 mice in combination is presented in this report. A total of 119 inbred mice of both sexes were put on long-term feeding trials. Group I consisted of 34 mice given a standard diet; group II of 32 mice fed an experimental diet containing saccharin coated betel nut powder at 10% concentration; group III of 29 mice given 0.2 ml aqueous solution of 0.1% 1,4-dinitrosopiperazine by intubation daily and group IV of 24 mice fed a combination of the experimental diet together with intubation of 1,4-dinitrosopiperazine. Feeding was continued for 40 weeks at which time all mice were given a standard diet and water ad libitum, and then observed for their full life-span. The commonest neoplasm found was squamous cell carcinoma of the forestomach in groups III and IV. Male mice were more susceptible to the treatment than female mice. In female mice reticular cell neoplasm--Type A of the uterus was the commonest tumour and was more common in group III than in group IV. The diet of saccharin coated betel nut failed to potentiate the carcinogenicity of 1,4-dinitrosopiperazine.