A new plateau in the dose-survival-time response of the golden hamster (Mesocricetus auratus) from whole body irradiation.

The survival time of golden hamsters (Mesocricetus auratus) after whole-body 60Co-gamma-irradiation in the range of 600 to 200 000 rad was investigated. The two plateaus of the dose-survival curve which correspond to bone marrow and gastrointestinal death are similar to those of other species such as mice, rats and mongolian gerbils. A new plateau occurring 40-57 hours after doses of 30 000 to 60 000 rad, where there is a little reduction in survival time, has been found. It is in addition to the well recognized central nevous system (CNS) syndrome. This plateau is observed only in golden hamsters, presumably because of their relatively high resistence to CNS syndrome. Experiments involved partial body irradiation of the animals indicate that the target is in the cephalic one-third of abdomen. The new segment may well indicate a new type of acute somatic radiation injury different from the well known bone marrow, gastrointestinal and CNS syndromes.