510 ADVEXTURES IK RADIOISOTOPE RESEARCH 



by the simple physico-chemical law of penetration. In such consideration 

 we must always envisage the fact that it is not the concentration differ- 

 ence of the ion in the corpuscle water and the plasma water which 

 matters, but the deviation from the equilibrium distribution ratio which 

 can, and often does, deviate considerably from unity. 



A closer analysis of the happenings in the corpuscles reveals the 

 following facts. The high phosphate content of the corpuscles is due to 

 an incorporation of a very substantial amount of phosphate in the mole- 

 cules of adenosintriphosphate, hexosemonophosphate, diphosphogly- 

 cerate, and so on. These molecules are incessantly degraded and rebuilt 

 in the course of the metabolic circle going on in the corpuscles. The larger 

 part of the phosphate present in the corpuscles is thus incorporated into 

 organic molecules and is no longer free phosphate. The maintenance 

 of the great difference in the acid soluble P content of the corpuscles 

 and of the plasma is thus dependent on the metabolic circle going on in 

 the corpuscles. The accumulation of ions in plant and animal cells is 

 found to be generally conditioned by metabolic processes going on in 

 the organism; in the case of concentration of phosphate in the corpuscles 

 the way in which the metabolic process performs the ionic concentration 

 is clearly shown, while we are in the dark in other cases as to the mecha- 

 nism of the process of accumulation. This mechanism may he built up 

 in some other cases on similar lines as described above. 



RATE OF PENETRATION OF LABELLED CHLORIDE INTO 



THE CORPUSCLES 



We arrived at the result that phosphate penetrates at a fairly slow- 

 rate into the corpuscles. When making this statement we compare the 

 rate of penetration of phosphate with the rate of intrusion of chloride. 

 Chloride ions are known to penetrate speedily into the corpuscles. The 

 increase of the COg content of the blood is followed by an increase in 

 the bicarbonate content of the erythrocytes. As a result of the increase 

 in the bicarbonate content of the corpuscles, bicarbonate will move 

 from the erythrocytes into the plasma and chloride from the plasma into 

 the corpuscles. The interchange between chloride and bicarbonate 

 which is intimately connected with respiration processes is very fast, 

 in about 2 seconds half of the equilibrium distribution is reached (Dikken 

 and Mock, 1931). 



In view of the very small resistance the chloride ions encounter when 

 penetrating the corpuscle membrane, we can expect the chloride ions 

 not only to interchange speedily with HCO3"" ions but also with other 

 Cl~ ions. Labelled CI" ions introduced into the plasma will soon be 

 found in the corpuscles, and vice versa. 



