INDUCTION OF LEUKEMIA AND AMYLOIDOSIS IN SENILE C57BL MICE BY ORAL FEEDING OF 3-METHYLCHOLANTHRENE IN OLIVE OIL SOLUTION

Abstract

A low-spontaneous leukemic strain C57BL is said to be susceptible to leukemogenic treatment by X-ray irradiation but not to chemical carcinogens. In the present experiment, 136 senile C57BL mice were treated with a single intragastric instillation of 3-methylcholanthrene-olive oil solution and, as a result, leukemia appeared at 62 to 73 weeks of age in 8 of 57 males with 0.25mg, 9 of 39 females with 0.25mg, and 25 of 40 females with 0.5mg methylcholanthrene, or at the rate of 14, 23, and 600%, respectively.
The majority of the leukemias, i.e., 24 out of 42, was myelogenous in origin but 15 lymphogenous leukemia and three reticulum cell sarcoma were also observed. Five to six animals in each group developed systemic amyloidosis in the spleen, liver, and occasionally in the kidney. This amyloid showed autofluorescence similar to that of methylcholanthrene when a frozen section stained with Hematoxylin was observed under a fluorescent microscope.
The susceptibility to chemical carcinogen and senility in relation to physiological hematology of this strain of mice was discussed as a possible explanation of leukemogenesis in senile mice. Amyloidosis induced by chemical carcinogen was also examined to investigate its pathogenesis.