PHYSIOLOGY OF RADIATION INJURY 973 



tion in the presence of a rising plasma volume suggests an increased 

 breakdown of tissue that liberates protein, a failure of mechanisms of 

 proteolysis, or an increased synthesis of protein. Animals exposed to 

 small daily doses of X rays do not exhibit an initial decline in plasma pro- 

 tein, and in the terminal period total protein may rise, fall, or remain 

 unchanged (Prosser and Moore, 1946; Fink, 1946). Definite changes in 

 plasma protein have not been seen in irradiated patients (Frieden and 

 White, 1950). 



The albumin-globulin ratio as determined by salt fractionation is 

 elevated for several days after irradiation of the guinea pig or rat (Kohn, 

 1950, 1951a). The early increase in the A/G ratio is thought to be due 

 to the presence in plasma of an ether-soluble factor that affects the 

 fractionation procedure (Volkin and Kohn, 1950). There is no charac- 

 teristic change in the electrophoretic pattern of plasma proteins in dogs 

 during the first postexposure week (Muntz et al'., 1949). Albumin is 

 only slightly diminished during this interval, but a marked decrease, 

 amounting to 50 per cent, is found during the second week. Several days 

 before death the a-globulin fraction increases sharply, especially the 

 a 3 and a 4 fractions, and may actually be doubled. The /3-globulin- 

 fibrinogen complex is also increased but not so markedly as that of the 

 a-globulin. Similar changes occur in dogs treated with daily doses of 

 X rays or injected with Sr 89 and Pu 239 (Prosser, Painter, Lisco, et al., 

 1947). Differences in the electrophoretic pattern have been noted in 

 dogs and goats after X irradiation (Buchanan and Barron, 1947). In the 

 latter, increase in the jS-globulin-fibrinogen fraction predominates and 

 little change is seen in the a-globulin. 



In contrast with the results observed in X-irradiated dogs, in neutron- 

 irradiated rabbits there is an initial decrease in the y-globulin fraction 

 which parallels the decline in leukocytes (Sanigar et al., 1947). This, 

 however, is followed by the increase in globulins and decrease in albumin 

 that is seen with X rays. Direct neutron irradiation of blood plasma 

 does not influence the electrophoretic pattern. The changes observed in 

 irradiated animals are nonspecific and related presumably to tissue 

 destruction, infection, and inanition. Similar patterns have been found 

 after thermal and other injuries and after the injection of adrenal cortical 

 hormones (Gjessing and Chanutin, 1947, 1950). It is not known whether 

 the diminution in albumin is due to impaired synthesis or to its loss from 

 the blood because of altered capillary permeability. Albuminuria is not 

 evident (Muntz et al, 1949). 



Plasma nonprotein nitrogen rises by over 25 per cent in rats and guinea 

 pigs during the first few days after exposure to X rays (Kohn, 1950, 

 1951a). On the other hand, there is little change or a gradual decline in 

 the dog until the terminal period when a marked increase is manifest 

 (Prosser, Painter, Lisco, et al, 1947). A definite elevation of NPN and 



