Influence of Heavy Ion Particle Irradiation in Mature Female Rats: the Life Span and Tumors and Bone Damage

Influences of heavy ion particle exposure to mature rats were examined to estimate the risk of space radiation. Female Wistar rats, 12 months old, were divided into four groups. Rats of three groups (each group, n=40) were irradiated to the whole body with heavy ion particle (Carbon 290MeV) at doses of 0.75, 1.0 and 5.0Gy. Rats in other group (n=50) were as the control. Rats were bred in a cage until they died and checked tumors and alterations. Histological examination was performed. Bone mineral density, shape and fragility (strength strain index) of tibia were measured by pQCT and the proximal metaphysis was used for histomorphometry. Femur was for strength by three point bending method. The life span after irradiation in each group were 394 +/- 115 days in the 0.75Gy group, 397 +/- 91days in the 1.0Gy group, and 111 +/- 141days in the 5.0Gy group, significantly (p