マウス白血病の発生機構に関する実験的研究

第1編 20-Methylcholanthreneの新生児マウス接種による白血病誘発に関する研究

抄録

1. A single subcutaneous injection of 1mg. of 20-methylcholanthrene in various strains of newborn mice resulted in the induction of leukemia in 23.1% (3 of 13) of AKR, 15% (3 of 20) of St. A, 50% (7 of 14) of RF, 20% (5 of 10) of DB, 12% (3 of 25) of C3H, and 7.1% (1 of 14) of Zb during an observation period of six months, but no leukemia development was seen in strains D103, Cb, Swiss albino, RIIl and in each control group of mice.
2. The same carcinogenic treatment induced subcutaneous sarcomas in 30.8% (4 of 13) of AKR, 42.9% (6 of 14) of RF, 20% (2 of 10) of DB, 35% (7 of 20) of St. A, 48% (12 cf 25) of C3H and 21.4% (3 of 14) of Zb. Strains D103, Cb, Swiss albino and RIII, which were refractory to the leukemia development, also developed subcutaneous tumors in 23.4%, 40%, 25% and 40% respectively.
3. Furthermore, induction of pulmonary adenomas was observed in AKR, St. A, RF, C3H and DB mice.
4. Histological examination of leukemic mice revealed infiltration of leukemic cells in bone marrow, lymph nodes, liver, spleen, thymus and kidneys. The diagnosis of leukemia was also confirmed by means of clinical tissue culture.
5. Strains C3H and AKR, 4 weeks old, were given a subcutaneous injection of 20-methyl-cholanthrene in the same doses per body weight as in newborn mice. However, after 26 weeks of observation period only subcutaneous sarcomas were observed in 4 of 10 C3H mice and 2 of 9 AKR mice.
6. Newborn mice born of parents given 20-methylcholanthrene at birth were again injected with the carcinogen. Induction of leukemia in these mice was 44.3% (3 of 7) in RF mice and 21.3% (3 of 14) in AKR mice during an observation period of six months, and the procedure did not significantly diminish the latency or increase the rate of leukemia development. How-ever, the rate of sarcoma development was increased in AKR, St. A and D103 mice.
7. During serial cell-graft of leukemia in RF mice a change from non-thymic to thymic type was observed.