The effect of diethylhydroxylamine on the incidence of tumors induced by benzo(a)pyrene in the mouse.

Groups of 20 male and 20 female CD-1(ICR)Br mice were treated either with 0, 3, 30, or 300 mg diethylhydroxylamine (DEHA)/kg-day (administered via the drinking water) from 57-112 days of age. For the four week period between 70 to 98 days of age, all animals received (via gavage) eight 1 mg doses of benzo(a)pyrene at 4 day intervals. One hundred thirty-seven animals survived the dosing period. Of these, 132 survived to 211 days of age at which time they were euthanized and necropsied. Gross lesions were observed only in the lungs and squamous portion of the stomach. Treatment with DEHA produced no significant effect on the lung tumor incidence of either sex. However, a significant increase in stomach tumors was observed in the females.