Induction of Leukemia in Mice

Abstract

Young [male] and [female] mice of strains, F, A, and sublines 12 and 212 of strain dba were observed as untreated controls, and during and following adm. of x-rays or methylcholanthrene. 80 r of x-rays were given daily up to 720 or 880 r. Methylcholanthrene was given percut. twice weekly in a 0.5% soln. in benzene. 55% of the F strain developed spontaneous leukemia, 30% were readily susceptible to methylcholanthrene induction of leukemia, and all resisted x-ray induction. Strain A was low in spontaneous leukemia, resistant to methylcholanthrene induction, but showed a 30% incidence with x-rays. Subline 212 was moderately susceptible to spontaneous leukemia, markedly influenced by methylcholanthrene, but resisted x-rays. Subline 12 resisted spontaneous leukemia, but was very susceptible to methylcholanthrene. Susceptibility to one agent, or to spontaneous disease, is not necessarily correlated with susceptibility to other leukemogenic agents.