HOWARD H. VOGEL, JR., DOX\ L. JORDAN AND SAMUEL LESHER 

 RADIATION PROTECTION EXPERIMENTS 



Comparative Effects of Single, Postirradiation Intravenous Injection of 

 Bone-Marrow Cells in Mice Irradiated with Lethal Doses of Fission 



Neutrons and ^K^o y-Rays 

 CF No. 1 female mice, six to eight weeks of age, were exposed to a single 

 dose of fission neutrons or of ""Co y-rays suflSciently high so that 95-100 per 

 cent would die within 30 days. The exposures were carried out in the 

 gamma-neutron radiation chamber^ at the CP-5 research reactor. Ninety- 

 four mice were exposed to 360 rad of fission neutrons in 100 min with the 



90 

 80 

 70 

 60 

 50 

 i,0 



2 20 



10 



/ 



/ 



// 

 // 



.,-^- 



Fission neutrons 

 ~ 360 rad 

 (100 min) 



Bone marrow 



(A8) 



Tyrode's solution (A6) 



Bone marrow (35) 

 Tyrode's solution (3A) 



30 



10 15 20 



Days after irradiation 



Figure 2. Comparative effects of single, postirradiation 



intravenous injection of homologous bone marrow cells 



in mice irradiated with lethal doses of fission neutrons 



and ooCo y-rays (1082 r) 



reactor operating at 1000 kW; 69 additional mice were exposed to a single 

 dose of 1082 r of "^"Co y-rays delivered at an intensity of 13 -3 r/min. Each 

 series of irradiated mice was then subdivided into two groups, the first 

 receiving an intravenous injection via the tail vein of 0-2 c.c. bone-marrow 

 cells in Tyrode's solution, the second half receiving 0-2 c.c. of Tyrode's 

 solution only. All injections were completed \vithin a few hours follo\ving 

 irradiation. 



The bone-marrow cells were obtained from the femora of other CF No. 1 

 female mice of approximately the same age as the irradiated animals. The 

 donor mice were sacrificed with ether and both femurs were dissected free. 

 The head of each femur was then cut off and the cells were washed out of 

 the marrow cavity into a small glass dish with a small amount of sterile 



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