A STUDY OF TOBACCO CARCINOGENESIS .51. RELATIVE POTENCIES OF TOBACCO-SPECIFIC N-NITROSAMINES AS INDUCERS OF LUNG-TUMORS IN A J MICE/

Tobacco-specific N-nitrosamines (TSNA) are formed from nicotine and th e minor Nicotiana tabacum alkaloids during tobacco processing and toba cco smoking. The TSNA are the most abundant strong carcinogens in smok eless tobacco and in smoke. In this comparative study six TSNA and two major volatile N-nitrosamines of cigarette smoke are assayed for thei r relative tumorigenicities in strain A/J female mice and for their po tential to induce lung tumors. N-nitrosodimethylamine was the most pot ent inducer of lung adenoma in the A/J mouse model followed in order o f decreasing potencies by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butano ne, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol, N-nitrosopyrrolidin e, N'-nitrosonornicotine and N'-nitrosoanabasine. 4-(Methylnitrosamino )-1-(3-pyridyl)-1-butanol and 4-(methylnitrosamino)-4-(3-pyridyl)butyr ic acid were inactive. The relative tumorigenic activities of the toba cco-specific nitrosamines in strain A/J mice compare well with the ava ilable data for their relative tumorigenic activities in F344 rats and Syrian golden hamsters.