INCORPORATION OF "C INTO TISSUE 



817 



Infest, 

 Mucosa 



Liver 

 r 



Lungs 

 r 



Muscles 



7 



Brain 



^ 



M 



-// 



Fig. 10. Uptake of ^^C by 1 mgm of dry tissue of iriadiated and of 

 control mice 90 min after intraperitoneal injection of NaCHj i^COO. 



Plasma 



Muscles 

 777 



^ 



Brain 

 r 



^ 



Bone 



yA 



Fig. 11. Uptake of ^*C by 1 mgm of dry tissue of irradiated and of 

 control mice 6 hr after intraperitoneal injection of NaCHj i*COO. 



from the intestinal mucosa of control animals was taken to be 100. 

 While as seen in Figs. 4 to 7 in the fully grown animal from all protein 

 fractions that of the intestinal mucosa has the largest i^(J content, for 

 the rapidly growing rat (cf. Fig. 8) this is no longer the case. 



A comparison of "C uptake by the fatty fractions of the organs of 

 the newly born and of outgrown animals exhibit very pronounced diffe- 

 rences as well. While in the outgrown mouse the ^^C content of 1 mgm of 

 brain fats amounts to a small percentage only of the corresponding value 

 of the intestinal mucosa fat, in the suckling rat the ^^C content of 1 mgm 

 of brain fats is higher than that of 1 mgm of intestinal mucosa fat, while 

 in the outgrown rat in experiments taking a few hours the ^^C content 



5 2 Hevesv 



