954 



ADVENTURES IX RADIOISOTOPE RESEARCH 



the application of such labelled corpuscles in the determination of the 

 total circulating red corpuscle content of the organism^'^- ''^\ A detailed 

 investigation of the erythrocyte content of human subjects, making use 

 of labelled corpuscles, was carried out by Nylin^'^"' ^^^ . He estimated, 



Distribution 

 Coefficient 



40 50 



min. 



7o 

 100 



ec 



> 



o 



° 40 



Fig. 7. — Distribution of labelled ions between corpuscles and 

 plasma of equal weight at 37°. 



20 - 



"p'x^M — — I — — ^""f H — f'l^^^^^ — ^ 



A 1 I ' i 



O 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 



Seconds Gfter injection 



YiG. 8. — Change of activity of the arterial corpuscles with time 

 following intravenous injection of labelled corpuscles. (G. Nylin). 



furthermore, the rate at which injected blood and the circulating blood 

 are homogeneously mixed. Figure 8 shows the result obtained by Nylin 

 in an experiment where homogeneous distribution of the injected blood 

 took only 60 seconds. 



Corpuscles can also be labelled by introduction of radio-iron into the 

 corpuscle haemoglobin. Such corpuscles were used by Hahn and his 

 colleagues ^'^^ in the determination of the red-corpuscle content of the 



