The Effect of Radiation on the Survival in Vitro of Rat Thymocytes of Different Size

Publisher Website
Google Scholar
Abstract
The radiation-induced decrease in the survival of isolated thymocytes of different size was determined 5 hr. after a wide range of radiation exposures (10 to 1500 R; 60Co). The survival following all doses of radiation decreased as the cell size increased. The exponential dose-survival curves for each of the 5 size classifications consisted of 2 components; the percentage of survival decreased with doses up to about 300 R but became flat and independent of the radiation exposure at higher doses. The level of the flat portion varied inversely with cell diameter, decreasing from about 68% survival for the smallest (4.9 m) to 12% for the largest (10.4m) cells. Once thymocytes are lethally injured by radiation, the rate of degeneration is governed by the rate of physical and chemical processes within the cell; the speed of these processes increases as the cell size increases. The slopes of the dose-dependent component of the dose-survival curves were found to be similar for cells from 4.9 to 7.9m in diameter, but were 2- and 4-fold greater for larger cells, indicating an increased radiosensitivity among the large cells of the isolated population.

This publication has 13 references indexed in Scilit: