抄録
Four hundred seventy ddN female mice of 10 weeks old were divided into five groups : (1) whole body exposure, (2) head exposure, (3) trunk exposure (chest and abdomen), (4) lower body exposure (pelvis, legs and tail), and (5) non-irradiated control. All the exposure groups received a single x-ray dose of 40O R under anaesthesia. The mean survival times of five groups were 46.0±2.3 weeks for whole body exposure, 63.5±2.3 weeks for head exposure, 51.5±2.3 weeks for trunk exposure, 68.1±2.4 weeks for lower body exposure and 73.8±2.8 weeks for non-irradiated control. The exposure of 400 R to whole body, head, and trunk resulted in significant lifeshortening from that of non-irradiated group, while the exposure to lower body did not produce any significant life-shortening. The life shortening per volume dose for head exposure group was the highest among all the exposure groups. This suggests that head (brain included) may play an important role in the radiation-induced life-shortening.
