Presence of Leukemic Agent in Normal Testes and Ovaries of Young Mice of Ak Line

Abstract

Cell suspensions prepared from normal testes and ovaries, that were removed aseptically from young, healthy mice of the leukemic Ak inbred line, were inoculated subcutaneously into newborn, suckling mice of the C3H (f) line (in which the incidence of spontaneous leukemia is less than 0.5%). Of 12 C3H (f) mice inoculated with the testicular extract, 8 developed "spontaneous" leukemia at an average age of 11.8 months. Of the 14 C3H(f) mice inoculated with the ovarian extracts, 6 developed leukemia at an average age of 14.7 months. Leukemia that developed in the C3H(f) mice as a result of inoculation with either testicular or ovarian extracts could be transplanted, by cell transfer, to adult C3H mice, but not to mice of the Ak line. These findings suggest that the normal testes and ovaries of young, healthy mice of the Ak line contain an agent causing leukemia. Ak milk, recovered from stomachs of suckling Ak mice, was inoculated subcutaneously into 17 newborn C3H or C3H(f) mice, but none of them developed leukemia, suggesting thereby that Ak milk does not contain a leukemic agent. This result was consistent with previous experiments on foster nursing of Ak and C3H mice.