Abstract: 【ABSTRACT】 BACKGROUND ＆ AIM: In order to explore an economical and effective method for building lung tumor model induced by diethylstilbestrol(DES), we studied the carcinogenic effect on neonatal mice treated by DES. MATERIALS AND METHODS: The newborn mice were divided into DES, urethan(U) and U＋DES groups. U was given in 500 mg/kg dose ip on the 14th day after they were born. DES was administered by ip on 1 d, 8 d, 15 d in the doses of 1/7(L), 2/7 (M) and 4/7 (H) LD50 of the day of treated. At 26 weeks old ,they were sacrificed and checked for the formation of tumors. The organ index ,tumor incidence ratio and mean number of tumors were calculated. RESULTS: Lung tumors were obviously induced in tested neonatal mice. The incidence of lung tumor of DES(L,M,H) groups were 16.7％, 22.4％ and 43.1％, the U＋DES(L,M,H)) were 70.4％,90.9％ and 70.8％ respectively, and the U group was 53.1％. The mean numbers of lung tumors of U＋DES(L,M) were higher than the DES(L,M) respectively (P<0.05). CONCLUSION: High incidence of lung tumor could be induced by the combined action of DES and U in neonatal mice, which may be an useful and economical method to establish a lung tumor model.

Key words: diethylstilbestrol, newborn mice, tumor model, lung tumor