Radiosensitivity of malignant tumours

Tumour tissue has been transplanted to 5 groups of rats to study the effect of general pre-transplantation X-ray irradiation of the recipient on the effect of transplantation of the irradiated tumour tissue. In the first group - the suspension of native timour tissue has been transplanted to intact rats; in the second group - the suspension of native tumour tissue has been transplanted to rats that have formerly been subjected to a single immunization with subcutaneously irradiated timour material; in the third group - the suspension of native tumour tissue has been transplanted to totally irradiated animals; in the fourth group - the syspension of irradiated tumour tissue has been transplanted to intact rats; in the fifts group - the suspension of irradiated timour tissue has been transplanted to totally irradiated rats. The reseach has shown that there exists a weak antitumoral immunity that manifests itself only at the time of gratting tumour tissue in a small amount. In this case one can observe the decrease in the tumour development in rats formerly subjected to the effect of lethally irradiated tumour cells and the increase of cell transplantation in totally irradiated mice. Transplanted irradiated 0.77 Coul/kg timour tissue in the irradiated organism develops better than in the organism of intact animals