[Experimental investigations on the accumulation of radioactive compounds in autochtonal tumors in the rat (author's transl)].

For the first time results of investigations on rats with radioactive compounds in autochtonal tumors of the central nervous system, induced via placenta by Ethyl-Nitrose-Urea (ENU), are reported. In contrast to transplantation tumors the tumors induced by ENU are comparable in regard to the szintigrafic results with human brain tumors. The radiopharmaceuticals 131I-HSA, 99mTc-Pertechnetate, 203Hg-Chlormerodrin and 113m/111In-DTPA are similar to human brain tumors taken up by the ENU-tumors. For these findings it may be important, that the ENU-tumors are of neurogenic origin and do not differ histologically from the human brain tumors. The accumulation of the radioactive substances in ENU-tumors can be explained with the lesion at the blood-brain-barrier and at the blood-nerv-barrier. Therefore, it is discussed that the mechanism of the uptake is similar in human brain neoplasms and in ENU-tumors of the brain. The ENU-tumor model is suitable for testing new radiopharmaceuticals before their application in men.