Effects of Radioactive Iodine on Free Sarcoma 37 Cells in the Peritoneal Fluid of the Mouse.

Abstract

CFW mice were inoculated intraperit. with S-37 cells and treated intraperit with I131 (0.2 or 0.4 mc). The fate of tumor cells was studied by repeated withdrawal and examination of peritoneal fluid in each mouse compared with control animals. The examination of each specimen of peritoneal fluid consisted" (a) in the microscopic assay of integrity and ability for multiplication (percentage of mitoses) of free tumor cells which multiplied in the peritoneal fluid before treatment, and (b) in the biological assay of viability of tumor cells, i.e., their ability to survive and multiply after transfer into new mice. The results indicate that with a single exception all tumor cells suffered loss of viability even after treatment with the minimal dose (0.2 mc ) of I131. In most mice this effect was detected only after the failure of tumor cells from treated animals to grow in the peritoneal fluid of new animals. In other animals, where higher dose of radiation was used or, presumably, where nutrient environment was drastically changed, the tumor cells disintegrated in the body of the treated mouse. Rapid disappearance from the peritoneal fluid of the radioactive prepn. suggested the differentiation between its early and primary effect and its later secondary effect.