Abstract
Yoshida sarcoma cells labeled with 131I-iododeoxyuridine were inoculated into Donryu female rats intraperitoneally. In these animals, the fractional rate of cell death and migration from the peritoneal cavity were monitored by measuring the radioactivity in the whole body and extraperitoneal site with a whole body animal counter. The radioactivity of the tumor cells in ascites fluid was measured by a well type scintillation counter. 3H-TdR-labeled Yoshida sarcoma cells were inoculated into Donryu female rats intraperitoneally. The radioactivity in the DNA fractions from the lungs, liver, spleen, kidneys, solid tumor on the omentum and the tumor cells in the ascites fluid was measured by a liquid scintillation counter 24 and 96 hours after the intraperitoneal inoculation in order to chase changes in the anatomical distribution of the 3H-labeled tumor cells. The results are as follows : (1) The death rate of 131I-IUdR-labeled tumor cells inoculated intraperitoneally was 6.3% per day. Six hours after the inoculation of the 131I-IUdR-labeled tumor cells, 18.5% of the radioactivity were in the extraperitoneal tissues, indicating rapid migration of tumor cells from the peritoneal cavity. The extraperitoneal radioactivity did not change until 72 hours after the inoculation, then it was increased at a constant rate to 32.1% 120 hours after the inoculation. The rate of cell loss from the ascites fluid was 9.2% per day until 48 hours after inoculation and thereafter it was increased to 17.0% per day. (2) Radioavtivity present in the lungs, liver, spleen and kidneys 24 hours after the inoculation with 3H-TdR-labeled tumor cells was 1.27±0.05%of the total amount of radioactivity administered. Ninety-six hours after the inoculation, radioactivity distributed in these organs and solid tumor on the omentum was 8.49±0.19%. From these results, solid tumor on the omentum, liver and lungs were seemed to be the major place of the tumor cell migration. It was concluded that the tumor cell death and the migration from the peritoneal cavity might participate a deceleration in the growth curve of the tumor cells in ascites fluid.
