Enhanced tumour development by butylated hydroxytoluene (BHT) in the liver, lung and gastro-intestinal tract.

Continuous feeding of 0.5 or 0.05% butylated hydroxytoluene (BHT) enhances the development of spontaneously occurring liver tumours in C3H mice, but not in BALB/c mice. In mouse lung, the tumour-enhancing effects of BHT vary with the carcinogen used. In the gastro-intestinal tract of mice and rats, BHT enhances the development of dimethylhydrazine-induced tumours, but is without effect on tumours produced by methylnitrosourea. Strain differences, the effect upon various carcinogens, paradoxical dose responses and mechanisms of action remain major questions in the toxicology of BHT.