Stimulation of DNA synthesis in mouse and rat lung following administration and butylated hydroxytoluene

Butylated hydroxytoluene (BHT) is a widely used antioxidant in food. It has recently been reported that intraperitoneal injection of BHT to female mice produced, within 3-5 days, a hypertrophy, hyperplasia, and general disorganisation of the cellular components of the lung (Marion and Mitchell, 1972). In male mice it was shown that this effect of BHT was associated with a marked stimulation of DNA synthesis in the lung (Witschi and Saheb, 1974). Measuring the incorporation of thymidine-2-14C into DNA in lung confirmed the results reported in mice. 500 mg of BHT per kg, i.p., resulted in a 20-40 fold increase in thymidine incorporation in both male and female mice after 4 days. In similar experiments in the rat, however, a two-fold increase was observed in female rats, no effect could be demonstrated in male rats. In experiments in male and female mice using p.o. administration of BHT similar results have been obtained as following i.p. administration.