EFFECT OF X-RAYS ON THE RESORPTION RATE OF INJECTED NaH^^COg IN MICE 



adrenaline may conceivably escape notice. Combining adrenaline injection 

 and irradiation in further experiments gave, however, not an additive de- 

 pression of ^''COg exhalation. Instead we found an increased output of 

 ^^COg amounting to about 30 per cent higher value than the controls. 



Thus, it is so far established that the actual concentration of free hormones 

 in the circulation interacts with the specific X-ray effect studied here, whereas 

 the mechanism of this reaction is obscure. Apart from this it would appear 

 that the effects may have some bearing on the general problem of studying 

 the biochemical effects of the irradiation using isotope labelled compounds. 

 Obviously the distribution of injected compounds in irradiated animals 

 relative to controls may shift rapidly during the first minutes. This may 

 occasionally induce misleading conclusions as to the irradiation effect 

 studied. 



A more detailed account of this work will be published elsewhere. 



REFERENCES 



1 FoRSSBERG. A., and Hevesy, G. Amer. J. Physiol., in press. 



^ Hevesy, G. and Forssberg, A. Nature, Lond. 1951, 168 692. 



^ Greenspan, F. S., Li, C. H. and Evans, H. M. Endocrinology, 1950, 46 261. 



" Kety, S. S. Amer. J. Med. Sac. 1948, 215 352. 



DISCUSSION 



Z. M. BAcq : I just want to call attention to the following point. 



Twenty years ago one spoke of days after irradiation. During the last years we 

 got interested in what happens 30 minutes or one hour after irradiation. Thanks 

 to Hevesy and Forssberg, one sees changes a few minutes after irradiation. This is 

 indeed going in the right direction. 



R. H. Mole : I wonder if Forssberg has considered whether changes in intestinal 

 movement or circulation could be responsible for the effect of radiation in decreasing 

 the turnover of an intraperitoneal injection. That changes do occur during or 

 within a few minutes after irradiation was shown by Conard. 



150 



