Hematological Effects of Partial-Body and Whole-Body X-Irradiation in the Rat

As early as 1905, Helber and Linser (1) investigated the effect of X-ray exposure on red blood cells, platelets, and hemoglobin. Since then data concerning hematological changes after whole-body exposure to most types and widely varying doses of ionizing radiation have been published (2-7). In more recent years interest in the effects of partial-body as compared to whole-body exposure has also developed. In his analysis of the only wartime experience with radiation exposure, Sams4 reports that most of the radiation casualties were indeed cases of partial-body exposure. Similarly most therapeutic and many accidental exposures have been partial-body in nature. The mechanisms of death in most mammals after whole-body acute exposures have been well documented. The primary cause of death is usually due to hematopoietic, gastrointestinal, or central nervous system failure, depending on the magnitude of the exposure. In the case of partialbody exposure, however, particularly upper-body exposure in the midlethal range, the cause of death is not so clearly defined. The time of death after a midlethal upper-body exposure in rats (8, 9) or in dogs (10) is similar to that for the whole-