Tissue factor from rat liver which promotes transplanted cancer growth has been reported by many authors.
The following experiments were conducted to investigate more precisely the effect of promoting factor extracted from human plasman on the transplanted cancer of mouse and rat, as well as on normal tissue growth of mouse.
Materials and Methods.
For animal cancers, Ehrlich cancer and Yoshida sarcoma were used. Tumor transplantations were performed following Hwang and Kim.
1) Promoting factor of plasma was prepared in the following manner: human plasma was centrifuged in an International Centriguge Model PR_1 at 15,000 r.p.m, 95% ethyl alcohol was added to the supernatant. precipitation was removed, and the supernatant was dried The dried material was prepared for injection into 5% solution with physiological saline.
2) To investigate the effect of plasma factor on the tumor growth, injections were carried out after tumor transplantation in mouse with Ehrlich cancer and in rat with Yoshida sarcma. A singel dose of 0.1 ml., 0.2 ml., 0.3 ml., of the plasma factor solution in cancer mouse and 0.5 ml., 1.0 ml., 1.5 ml., of plasma factor lolution in cancer rat was injected intraperitoneally in individual animal group once daily for 18 days consecutively. On the 18th day after tumor transplantation, animals were sacrificed and tumors removed and weighed. The growth of tumors were measured by the average of 2 diameters of the tumors and these compared with those of control groups every 3 days.
3) To investigate the effect of plasma factor on mitosis of normal mouse tissue, a single dose of 0.2 ml. of 5% solution of plasma factor was injected intraperitoneally once daily for 18 days consecutively. The animals were sacrificed every 3 days and the liver and kidney were removed, fixed in Carnoy´s solution. After dehydration, the tissues were embedded in paraffin, cut in sections of 5 micron thick, and stained with hematoxylin and eosin. Mitoses were counted in 100 fields on each slide with the help of 970 multiplication. These counts were compared with those of the control group in which saline solutions were injected instead of plasma factors. The toxic effect of this plasma factor was studied in normal mouse. As shown in table 9, the toxic reaction was negligible in normal aimals in this experiments.
Results
1) The human plasma factor promotes markedly growth of animal transplantable cancer, having shown also an increase of the promotion as the injecting dosage being increased within the limit of a single dosage, while in over limit dosage the promotion seems to be decreased.
2) The human plasma factor promotes markedly the mitosis of normal tissues. On the otherhand, promotion of cellular mitosis is sustained by continuous administration of plasma factor, but is most marked at a certain dosage. Further increase of injections results in decline of the rate of such promoting action gradually.
3) The mitotic action of the human plasma factor is more enhanced in liver tissue than in kidney.
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