990 



ADVENTURES IN RADIOISOTOPE RESEARCH 



together with 0.7 mgm of inorganic phosphorus, ^2? of negligible weight 

 and having an activity oi 1 fic moves into the corpuscles, after injection 

 of the labelled corpuscles into an inactive circulation the migration of 

 0.7 mgm of inorganic P from the red corpuscles into the plasma will be 

 followed by that of about 0.1 f^c. only (cf. Figs. 11 and 12). This is 

 because most of the ^2? (and ^iP) after having penetrated into the red 

 corpuscles finds a temporary abode in the organic phosphorus compounds 



Plasma 



Red corpuscles 



Fig. 11. — Distribution of 

 inorganic phosphate intruded 

 into the red corpuscles between 

 organic and inorganic fractions 



Fig. 12. — Interchange of ^^P 



and 22p between plasma and 



red corpuscles 



+ 



0,7 mg ^'P 



I 



I 

 0,7 mg ^'P 



I microcurie-''P 



0,7 mg ^'P 

 I 



0,7mq^'P _-^ 

 H ► 



IQ microcune ■^'P 



present in the erythrocytes. About 1/10 represents the ratio of the inor- 

 ganic P content of the plasma and labile P content of the red corpuscles. 

 This ratio, and correspondingly the time during which ^2? is kept in 

 the erythrocytes, may vary for the blood of different subjects. The perme- 

 ability of the red corpuscle membrane, which is also of importance for 

 the temporary conservation of 32p in the corpuscles, may vary as well. 

 The loss of the ^ap content of the corpuscles in the course of 20 minutes 

 is, however, in no case larger than 3%, and in most cases even appreci- 

 ably less. When not labelled corpuscles but labelled blood is injected 

 into the circulation, loss of ^sp by the corpuscles during the experiment 

 can furthermore be compensated to an appreciable extent by uptake 

 of 32P from labelled plasma present in the circulation. 



(■"> Ark. Kemi 20, A Nr. 17 (1945); cf. Reeve and Veall, J. Physiol. 108, 12 

 (1949). 



