380 ADVENTURES IN RADIOISOTOPE RESEARCH 



gly cerate of the corpuscles. As an effect of pyloric obstruction, an in- 

 crease of the acid soluble P content amounting to 37 mgm. equiv. per kgm 

 corpuscle water of the clog was found to take place. From this increase, 

 32 mgm equiv. were due to the rise in the glycerophosphate content. 



These and numerous other findings clearly show that the acid soluble 

 phosphorus compounds of the red corpuscles are readily synthesised 

 and decomposed in the blood through reactions of the glycolytic cycle. 

 That these processes take place in the corpuscles at a remarkable speed 

 was shown by us when making use of radioactive phosphorus as an 

 indicator. We have, thus, two independent lines of evidence as to the 

 remarkably high rate of turnover of phosphoglycerate and some other 

 phosphorus compounds present in the corpuscles. 



By comparing the specific activity of the inorganic P of the corpuscles 

 with that of the P extracted from various organic compounds present 

 in the corpuscles we get information on the rate of resynthesis of these 

 compounds. The comparison of the specific activity of the inorganic P 

 present in the corpuscles with that of the inorganic P present in the 

 plasma informs us, on the other hand, on the rate of penetration of 

 phosphate ions from the plasma into the corpuscles. 



2. Rate of new formation of the acid soluble P compounds present 

 in the corpuscles 



As seen in Table 7, which gives the result of experiments in vitro, 

 the product of 7 min hydrolysis has, after the lapse of 30 min, a specific 

 activity amounting to 77 per cent of that of the corpuscle, inorganic P. 

 The product hydrolysed between 7 min and 12 hours, which contains 

 besides hexosephosphate P and other fractions appreciable amounts 

 of diphosphoglycerate P as well, is markedly less active than the readily 

 hydrolysed fraction, while the specific activity of the P of the non- 

 hydrolysed residue is only 1/8 of that of the corpuscle inorganic P. 

 This fraction^^^ consists mainly of 2, 3-diphosphoglyceric acid P though 

 it contains also P of the adenylic acid which amounts, in the corpuscles 

 of the rabbit, to about 5 — 10 mgm per cent, thus to about 1/10—1/20 

 of the total acid soluble P of the corpuscles. 



In experiments in vivo taking about four hours, all but the non- 

 hydrolysed fraction were found to be entirely renewed; only about 

 1/5 of the last mentioned fraction, presumably mainly its adenylic acid 



(i) E. Greenwald, J. Biol. Chem. 63, 339 (1925); H. Jost, Z. phi/siol. Chem. 

 116, 171 (1927); S. E. Kerr and A. Autaki, J. Biol. Chem. 121, 531 (1927); E. 

 Wabweg and G. Stearns, J. Biol. Chem. 115, 567 (1936); S. Rappaport and 

 G. M. Guest, J. Biol. Chem. 129, 781 (1939); A. Lennerstrand and M. Lenner- 

 STRAND, Ark. Kemi, 13, B, No. 15 (1939). 



