ENHANCEMENT OF ADENOMA FORMATION IN MOUSE LUNG BY BUTYLATED HYDROXYTOLUENE

Male mice, 6-8 weeks old, were injected ip with a single dose of urethan, an agent known to produce lung adenomata within 14-24 weeks after administration. When urethan was followed by weekly ip administrations of butylated hydroxytoluene (BHT), the number of tumors per lung found 14 to 24 weeks after urethan was increased. Increased numbers of tumors per lung were also found when the interval between urethan injection and the first BHT treatment was extended up to 6 weeks. When the total number of BHT injections was reduced from 13 to 4, tumor development was still enhanced. Repeated treatment with BHT, followed by urethan, had no effect and concomitant administration of urethan and BHT reduced the number of tumors found. BHT did not produce more tumors per lung in mouse strains resistant to adenoma formation. It is concluded that, in mouse lung, BHT has several properties of a promoting agent for urethan-initiated adenoma formation. © 1979.