同系可移植性しゅように対する移植早期における宿主防ぎょ能の定量化と防ぎょ能に影響する諸因子

Abstract

This report demonstrates a quantitative method of measuring host defense against syngeneictransplantable solid tumor (mammary adenocarcinoma 755 raised in C 57 BL/6 female mice). Three preparation methods, solid tumor mass, screen-meshed tumor cells and trypsin treatedtumor cells, were investigated. In these methods screen-meshed tumor cells were easilyobtained and fairly quantitative. Since tumor cells were inoculated into the left hind footpadof syngeneic mice, the kinetics of tumor growth during the early stage (from the time of tumorcells inoculation to that of footpad reaching about 3. 6 mm) were simply expressed by the twoparameters of latent period and rate of increase. Some factors affecting these parameters oftumor growth were next investigated. Sex differences were observed. The latent period wasaccerelated in female mice at 24 weeks old, but the rate of increase in both sexes was notdifferent. Aging in male mice, from 5 to 60 weeks, affected the latent period which wasgradually prolonged with aging, but the latent period in female mice was not affected by age. No correlation between the rate of increase and aging was not observed in either sex. Doseof dead tumor cells did not affected tumor growth. Latent periods were significantly prolongedin mice after thymectomy and 600 R whole body irradiation as compared to that of untreatedmice, but were somewhat shortening in mice receiving thymus cells after thymectomy andirradiation.On the other hand the rate of increase in untreated mice and the mice receiving more than1×107 thymus cells were lower than in irradiated mice and the mice receiving fewer than 1×10 7 thymus cells. Bone marrow cells significantly prolonged the latent period, in proportion tothe dose.Latent period in mice treated with antimacrophage agent (ferritin) was significantlyaccelerated.