HEMATOLOGIC EFFECTS OF RADIATION 1001 



a decrease in leukocyte values, but only one had a marked leukopenia. 

 In most dogs the sedimentation rate was increased. Liver function 

 tests were essentially negative. The hemoglobin and hematocrit values 

 decreased over a period of several weeks. 



GALLIUM (Ga 72 ) 



Dudley, Louviere, and Shaw (1951) administered radiogallium as a 

 citrate to five species of animals. The only effect of radiation observed 

 was a reduction in total leukocytes in the mouse, rabbit, and guinea pig 

 with dosages of 2.3-9.0 mc of Ga 72 /kg. The degree and duration of the 

 leukopenia vary with the dose and species. Repeated injections of 

 Ga 72 in dogs and rabbits indicated that this element is a cumulative 

 poison for these species. 



MORPHOLOGIC CHANGES IN PERIPHERAL-BLOOD CELLS 

 PRODUCED BY IONIZING RADIATIONS 



Morphologic changes in the various cellular constituents of the periph- 

 eral blood of animals, which are observed after exposure to penetrating 

 radiation such as X ray, fast neutrons, and radioactive elements, have 

 been described by a number of authors. These morphologic alterations 

 are not specific for the various types of radiation. In fact, all the morpho- 

 logic abnormalities that have thus far been described can be produced by 

 such radiomimetic substances as the nitrogen mustards. Exposure to 

 repeated small dosages of X rays or fast neutrons produced little or no 

 morphologic change except macrocytosis and, occasionally, the appear- 

 ance of giant platelets. Whether or not an anemia develops in mammals 

 exposed to ionizing radiation given in repeated dosages depends on the 

 sensitivity of the species and the size of the dose. In the event that 

 anemia develops, then all the characteristic morphologic changes are 

 seen in the red cells, e.g., anisocytosis, poikilocytosis, and macrocytosis. 

 The observations of Lorenz, Heston, et al. (1946) on mice, guinea pigs, 

 and rabbits exposed to dosages as high as 8.8 r/day until the accumulated 

 dose was 5000 r or more showed surprisingly little evidence of morpho- 

 logic change and form the basis for this statement. 



Exposure to a single dose of externally applied radiation, such as X ray 

 or fast neutrons, or irradiation from a single massive dose of an isotope 

 that localizes in the blood-forming tissue produced morphologic changes 

 that were detectable within a few hours after the exposure. These 

 changes, which have been described by Aubertin and Beaujard (1908), 

 Heineke (1904), Kroemeke (1926), Henshaw (1943-1944a, b), Evans 

 (1948), Dunlap (1942), Clarkson, Mayneord, and Parson (1938), Jacob- 

 son and Marks (1947), Jacobson et al. (1947), and Jacobson, Marks, and 

 Lorenz (1949), are briefly summarized. 



