HEMATOLOGIC EFFECTS OF RADIATION 



10G7 



LD 50 range and above, significantly decreases mortality. The mechanism 

 underlying this fact is not resolved, but studies by Patt, Straube, et at. 

 (1949) have conclusively shown that the recovery of the hematopoietic 

 tissue and subsequent return of certain constituents of the peripheral 

 blood occurred earlier in mice given estrogens before radiation than in 

 control irradiated nonestrogen-treated mice. The observed hematologic 

 effect of estrogen pretreatment indicates that a greater effect is exerted 

 on regeneration of granulocytes and erythrocytes than on lymphocytes. 



Other Prophylactic Measures. Sulfhydryl enzyme systems inactivated 

 by irradiation are reactivated in vitro by the addition of glutathione 

 and other similar compounds (Barron et at., 1949). Patt, Tyree, et at. 



80 

 70 



! P 32 INJECTION — 



I IHII! 



■'j^Zz. 



COBALT 



CONTROLS 



vyfc-P 32 PLUS 

 "'"' COBALT 



p32- 

 COBALT ADMINISTRATION 



INITIAL 



P 32 INJECTION 



PLUS P 32 PLUS 



COBALT 



19 22 25 

 Tl M E, weeks 

 Fig. 16-18. Effect of repeated injections (1.5 juc/g) of P 32 on the hematocrit values of 

 the peripheral blood of rats with and without cobalt-induced polycythemia. 



(1949) and Patt, Smith, and Jackson (1950) demonstrated that the 

 administration of cysteine just prior to total-body irradiation of rats and 

 mice increases survival of rats and, to some extent, hastens the recovery 

 of blood-forming tissue in rats. Glutathione has since been shown by 

 Cronkite, Brecher, and Chapman (1951) to produce an effect similar to 

 cysteine on survival of mice and on hematopoietic recovery. Enhance- 

 ment of hematopoietic recovery has been reported after severe oxygen 

 deprivation (Bennett, Hanson, and Dowdy, 1951), but no hematologic 

 data are available on animals subjected to cyanide intoxication during 

 irradiation (Bacq et al., 1950). The mechanism by which estrogens, 

 cysteine, or glutathione modify the hematologic picture is not known. 

 That the mechanism is different from the one observed after phenyl- 

 hydrazine or phlebotomy is clear since the destruction of hematopoietic 



