Modification of lung tumor development in A/J mice

Strain A mice were injected with urethan, 3-methylcholanthrene or dimethylnitrosamine and given repeated injections of butylated hydroxytoluene (BHT). This treatment significantly increased multiplicity of lung tumors induced by all 3 carcinogens. Two other antioxidants, butylated hydroxyanisole (BHA) or alpha-tocopherol (vitamin E) did not enhance tumor formation, nor did methylcyclopentadienyl manganese tricarbonyl (MMT), an agent capable of producing cell proliferation in lung. Lungs were more susceptible to the carcinogenic action of urethan 2 weeks following BHT-induced injury, but not during the phase of acute cell proliferation in lung. It is concluded that the effects of BHT on lung tumor development in mice are not related to its properties as an antioxidant or to its capability to produce extensive cell proliferation in lung.