Suppressive effect of aluminium chloride administration on mouse lung carcinogenesis by dimethylnitrosamine

Dimethylnitrosamine was administered to mice by ip injection once a week for 3 weeks and a high incidence of lung tumor was found 6 approximately 8 months after the final injection. In experiment I, the incidence of mice with lung tumors was 74% and the average number of nodules per mouse was 15.6 within 6.0 months after the final injection of dimethylnitrosamine. In mice given aluminium pretreatment, these values decreased to 65% and 6.7 (P less than 0.05), respectively. In experiment II, the incidence of mice with lung tumors was 100% and the average number of nodules per mouse was 8.7 within 7.5 months after the final injection of dimethylnitrosamine. In mice given aluminium pretreatment, these values decreased to 79% and 4.6 (P less than 0.05), respectively.