HEMATOLOGIC EFFECTS OF RADIATION 



1035 



tion accounts for leukocytosis. In view of the fact that two separate 

 peaks occur in this period, Jacobson et al. (1949) suggested that the first 

 peak might be accounted for by hastening of maturation in the bone 

 marrow and the second peak by a mobilization phenomenon in response 

 to widespread tissue injury by irradiation. Histologic studies by Bloom 

 (1947) have shown that the granulocyte peaks, described in the peripheral 

 blood, are seen especially in the lymphatic tissues; an "invasion" of 

 these tissues with granulocytes occurs concomitantly with the peaks 

 observed in the peripheral blood. 



10,000 

 8000 



6000 



200 



CO 

 3hr 



J — 1 L 



J L 



I 



8 



_L 



20 40 60 80 100 120 140 



CONTROLS 



TIME AFTER EXPOSURE, days 



— »25r o- a 50 r y ylOOr 



— o 500 r o a 600 r e— — e 700 r 



200 r 



800 r 



o- -o 300 r o- 



Fig. 16-3. Effect of single doses of total-body X irradiation on the heterophil values 

 of the peripheral blood of rabbits. 



Detailed studies on the effect of irradiation on the circulating eosino- 

 phils are not available. However, Aubertin and Beaujard (1908) 

 reported an increase in animals following irradiation, and Lawrence and 

 associates (1949) have reported an initial increase in dogs after an LD 50 

 exposure. 



The " Abortive Rise." An elevation in the lymphocyte, heterophil, and 

 reticulocyte values occurs in the rabbit after exposure to dosages of 300 r 

 and above (Figs. 16-1, 16-3). This elevation, first described by Jacobson 

 et al. (1947) and Jacobson, Marks, and Lorenz (1949), has been observed 

 by others in cats (Valentine and Pearce, 1952; Adams and Lawrence, 

 1947), dogs (Allen, 1947-1948), pigs (Cronkite et al, 1949), rats (Cohn. 

 1952; Suter, 1947), and guinea pigs (Lorenz, Uphoff, and Sutton, 1949). 

 The significance of this elevation, which appears generally between the 

 fourth and eleventh postirradiation day, is not known. It has been sug- 



