Prediction of Radiosensitivity of a Mouse from Its Physiological Characteristics before X-Irradiation

The animals used were 143 female mice, which were housed individually in metabolism cages. Their physiological characteristics were studied from the 8th week of age for 10 days. During this period of observation the mice were deprived of laboratory chow for 2 days. On the 11th day after the period of the observation they were subjected to a total-body X-irradiation with 660 rad, which resulted in${\rm LD}_{45(30)}$. Nineteen parameters, adopted as indicators of physiological characteristics of individual animals, were calculated from the daily changes in body weight, water consumption, urine volume, and the amount of urinary 5-hydroxyindoleacetic acid. When tested with their mean values none of these parameters showed a statistically significant difference between the survivors and the decedents, whereas by the method of quantification of Hayashi (a multidimensional analysis on these parameters), it was possible to predict the deaths of individual mice with a high rate of success.