X線及び20-Methylcholanthreneにより惹起せしめたRF系マウス白血病の無細胞濾液移植に関する研究

Abstract

ABS>The incidence of leukemia in RF mice exposed to a single whole-body irradiation of 350 r x-rays was 77.4%, in 41 out of 53 animals. In all, 20 developed the thymic and 20 the non-thymic lymphocytic leukemia, while only one developed myelogenous leukemia. The incidence of leukemia by 20- methylcholanthrene painting was 88% in 22 out of 25 animals. Of them, 12 developed lymphocytic leukemia and 10 myelogenous leukemia. Cell-free filtrates from the leukemic mice, which were induced by a single whole-body x irradiation, were inoculated to the newborn mice of the same strain less than 16 hours old. Two (18.7%) of the twelve inoculated animals developed leukemia on the 357th and 374th days, respectively, after the inoculation. Attempts to inoculate cell-free filtrate from 20-methylcholanthrene-induced leukemic RF mice to newborn mice of the same strain were successful. Cell-free filtrate from the myelogenous leukemic mouse caused lymphocytic leukemia in one of three inoculated mice. This is suggestive of the possibility of transformation of the type of leukemia during cell-free transmission. Virus-like particles were demonstrated by electron microscope in the lymph nodes of 20-methylcholanthrene-induced leukemic mice. The results suggest that x-ray and chemical carcinogens may act to induce leukemia or mammary carcinomamore » by the activation of a latent virus naturally resident in the RF mouse. (P.C.H.)« less