[Role of the cellular inoculation dose in the development of the inhibitory effect of transplantable tumors on metastasis].

The study was concerned with a relationship between the influence of subcutaneously (s/c) transplanted LS and MMT1 tumors in a syngeneic system on the development of spontaneous and experimental lung metastases in mice and the dose of transplanted tumor cells. It was shown that the development of spontaneous of metastases in the lung depends on s/c transplanted tumor cells dose. Tumor inhibitory effect on experimental lung metastasis formation became apparent at doses ranging 10(6) -6 X 10(6), it rising proportionally to the increase in the dose of transplanted tumor cells. This relationship was more pronounced in MMT1 tumor-bearers. The relationship of experimental lung metastasis development and transplanted tumor cells was reproduced in the system of adoptive transfer of tumor-bearers' splenocytes to intact mice (no other splenocytes than those in mice with tumors induced by 2 X 10(6) of transplanted cells were capable of any antitumor activity). The blood serum of tumor-bearing mice blocked the antitumor effect of splenocytes.