124 NEUTRON EFFECTS ON ANIMALS 



phoresis diagrams for normal rabbit plasmas, and the significance of the 

 additional component in these plasmas obtained after irradiation is not 

 known. 



Extremely abnormal plasma protein distributions, namely low albumin 

 concentrations but high concentrations of all the globulins and of fibrinogen, 

 were observed for the animals in this group which ^A'ere near death as a 

 result of irradiation. This finding is illustrated by the data given in 

 Table IV for rabbit No. 31, 140 days after completion of irradiation when 

 the animal was close to death. 



A comparison of these results foi rabbit Xo. 31 ^^^th those for rabbit No. 1 

 (which died 1 day after irradiation ceased) brings out the importance of the 

 rate of irradiation. It is apparent that sufficient time had not elapsed for 

 the irradiation to produce maximum abnormality in the plasma before rab- 

 bit Xo. 1 died as a result of the irradiation. 



Examined comprehensively, the results obtained in this study indicate 

 that the size of the unit dose, as well as the total irradiation received, plays 

 an important part in the response of animals to neutron irradiation. 



Direct Irradiation of Plasma. A large sample of plasma from a single 

 rabbit was diluted to one-third its original concentration with buffer, and 

 aliciuots in test tubes were sul^jected to irradiation doses of 0, 59, 440, 671, 

 and 2144 n. After irradiation, the samples were each dialyzed against 

 buffer and then examined electrophoretically. Xo significant differences 

 were observed in the electrophoretic patterns of these samples, showing 

 that direct neutron irradiation did not alter the protein distribution in the 

 plasma. 



DISCUSSION 



The primary effect on the plasma of both the irradiation procedures used 

 was a deciease in the 7-globulin concentiation. The changes in 7-globulin 

 concentration roughly paralleled the changes in total white cell count of the 

 blood. This relationship for animals treated with large neutron doses per 

 day is suggested by a comparison of the white blood cell data in Fig. 1 for 

 rab])its given 55 n/day doses ^\dth the data in Table III for the 7-globulin 

 concentrations of normal rabbits, and with those in Table IV for the 

 7-globulin concentrations of rabbits given 55 n/day. The correlation 

 between the white cell count and the 7-globulin content of the plasma is 

 stiengthened by the results obtained with rabbits given 10 n/day doses, 

 since in these experiments white cell counts and electrophoresis studies 

 were made at several different intervals after irradiation and, furthermore, 

 on the sam^e animals. (See the representative white cell data for rabbit 

 No. 29 in Fig. 1 and the data in Tables III and IV for the 7-giobuUn 

 concentration in tlie plasmas of rabbits Xos. 29 and 30.) 



