RENEWAL OF ACID SOLUBLE PHOSPHORUS COMPOUNDS IN OKiiAXS OF RABBIT liH 1 



content^i-, was found to be unchanged. Diphosphoglycoric acid is, llius, 

 renewed at a high rate as well. 



Rate of penetration of plasma inorganic P into the corpuscles 



To obtain information on the rate of penetration of the inorganic 

 phosphate of the plasma into the corpuscles, w-e have to compare the 

 specific activity of the plasma inorganic P with that of the corpuscle 

 inorganic P. After the lapse of 11.5 hours (see Table 3), this ratio is 

 found to be 4, showing that the rate of penetration of the phosphate 

 ions from the plasma into the corpuscles and vice versa is slows a much 

 slower process than the reorganisation of most of the acid soluble organic 

 P compounds present in the corpuscles. After the lapse of nine days, 

 the ratio of the specific activity of the plasma inorganic P and the cor- 

 puscle average acid soluble P is only slightly larger than 1 (1.06) (after 

 so long a time, the activity of the average corpuscle acid soluble P acqui- 

 red almost the same value as shown by the inorganic P of the corpuscles); 

 and after the lapse of fifty days, a completely proportional distribution 

 of the labelled P atoms between the plasma P and the P of the acid 

 soluble P compounds present in the corpuscles is attained. While, after 

 the lapse of 11.5 hours, the chance of a normal distribution of a P atom 

 which diffused into the corpuscles between organic and inorganic P is 

 almost 1, the corresponding figure for the distribution of an inorganic 

 P atom between plasma and corpuscles is only of the order of magnitude 

 of 1/4. 



The interesting phenomenon that an individual phosphate ion, while 

 penetrating fairly slowly into the corpuscles, is incorporated at a remark- 

 ably fast rate into organic molecules present in the corpuscles, finds 

 many analoga in the processes going on in various organs. It is especially 

 conspicuously shown in the study of the penetration of labelled phosphate 

 into the muscle cells and of that of the rate of renew-al of the acid soluble 

 P compounds present in these cells; the former process being slow, the 

 latter process being, in the case of some of the compounds, very fast. 



It is very probable that a large part of the P atoms present 

 in the molecules, of most of the acid soluble organic P compounds 

 of the corpuscles, were incorporated into these molecules inside the 

 corpuscles and reached the erythrocytes as inorganic phosphate ions 

 which passed from the plasma into the corpuscles. The possibility that 

 hand in hand with the process mentioned above a slow exchange of, 

 for example, organic phosphoglycerate between plasma and corpuscles 



^i) S. E. KERBandL. Daoud [J. Biol. Chem. 109, 304 (1937)] state that, out 

 of 88 mgm por oont organic acid soIuVjIo P found in tho coipusolos of tho labbit, 

 IG mgm per cent arc pyropliospliatc P and 8 mgni per cent adenylic acid P. 



