DISCUSSION 



The ascorbic acid of the suprarenals shows variations parallel to that of cholesterol 

 both in controls and cysteamine-protected rats. More than 300 rats have been used 

 in this study. 



We are not at all prepared to say that the cysteamine-injected rats survive because 

 their adrenals are in normal condition from the first to the fourth day. It might 



Cholesterol in suprarenals of rats mg/ 1 OOg 



— Irradiated controls 

 Irradiated under 



7 23 S cysfeamme 



2f f3 72 96 



Hours after 800 r whole body — ~ 



Figure 1 



very u ell be that the adrenals of these animals are in better shape because the liver 

 and other important organs have been less damaged in the presence of cysteamine. 

 The adrenals are not at all necessary for the demonstration of cysteamine action ; 

 recent observations of Fischer show that cysteamine protects adrenalectomized rats 

 against X-radiation. 



So far as I know, histological observation has not revealed changes in the supra- 

 renals as early as 1 hour after irradiation. 



Irradiation increases rapidly the amount of .\CTH present in the hypophysis ; 

 ACTH falls after 24 hours to subnormal levels*. In the pig, there is a marked 

 increase of neutral steroid excretion in the urine during the first day only, after 

 irradiation^. Thus the existence of a short hypophyso-adrenal reaction immedi- 

 ately after a heavy dose of X-rays seems undeniable. After 24 hours, the story is 

 indeed much more complicated. 



F. Devik®' " : In the discussion of morphological efTects of ionizing radiations it 

 may be of interest to point out that the mitoses in the bone marrow of mice may show 



pronounced radiation effects 1 hour or less after 200 r whole body X-irradiation. 

 These mitotic abnormalities, which mainly disappear in the course of 1-2 days, were 

 found to be significantly reduced in frequency by hypoxia treatment during irradia- 

 tion, and by pretreatment with cysteine, cystamine. and cysteamine as shown in 

 Table I. The figures indicate the mean percentage of abnormal anaphases. Usually 



311 



