988 RADIATION BIOLOGY 



diminished turnover of phospholipid and desoxyribonucleic acid phos- 

 phorus in the livers of irradiated mice and rats (Hevesy, 1946, 1947; 

 Kelly and Jones, 1950; Thomson, unpublished observations, 1951). A 

 further indication of altered metabolic function as a result of irradiation 

 is the finding that citrate accumulates in the livers of irradiated male 

 rats after fluoroacetate treatment in contrast to the lack of effect of 

 fluoroacetate in the nonirradiated animal (DuBois, Cochran, and Doull, 

 1951a). This may be attributed to an effect of radiation on the testes, 

 since castration also leads to an increase in liver citrate that can be pre- 

 vented by testosterone (DuBois, Cochran, and Zerwic, 1951b). Citrate 

 accumulation with fluoroacetate occurs in the nonirradiated female. 



Information relating to the effects of radiation on liver function is 

 nebulous and incomplete. Alterations in serum proteins produced by 

 radiation are not associated with significant changes in liver function as 

 indicated by the cephalin flocculation, colloidal gold, and thymol turbidity 

 tests (Schwartz et al.) 1948). Some decrease in the output of bile salts 

 has been seen when large dosages are delivered to the liver of the dog 

 (Smyth and Whipple, 1924). Terminal impairment of liver function 

 may be reflected by increased urinary excretion of urobilinogen and 

 coproporphyrin and the increased ratio of uric acid to allantoin (Schwartz 

 et al, 1948; Krizek et al., 1946; Miyazaki, 1937). Abnormal function 

 may also be indicated by the terminal rise in kynurenic acid excretion, 

 which is perhaps suggestive of some alteration in tryptophane metabolism 

 in the liver (Wattenberg and Schwartz, 1946a, b). 



Another aspect of liver physiology is referable to its reticulo-endothelial 

 elements. Although there is evidence of a decrease in the capacity of 

 fixed liver phagocytes of irradiated mice to remove intravenously injected 

 bacteria (Chrom, 1935), the uptake of a gold colloid by the reticulo- 

 endothelial system is not impaired nor is there an appreciable difference in 

 the fate of heterologous erythrocytes in normal and X-rayed animals 

 (Wish et al, 1952; Barrow et al, 1949). There is, in fact, some evidence 

 of an increase in phagocytic activity after irradiation. Yet, injury of 

 liver phagocytes by radiation may be of some consequence since lethality 

 has been shown to be potentiated when rats are injected with minimal 

 lethal dosages of P 32 and colloidal Au 19S (Friedell and Christie, 1951). 



KIDNEY 



The kidney is another example of an organ that appears to be resistant 

 to radiation, at least as judged by morphological studies. According to 

 Shields Warren (1942), dosages in excess of several thousands of roentgens 

 are required for renal changes. Kidney damage is generally not apparent 

 in irradiated animals (Hall and Whipple, 1919; McQuarrie and Whipple, 

 1922; Impiombato, 1935; Ely et al, 1947; W. Bloom, 1948), and the usual 



