Distribution of Phosphorus in Blood 



133 



65 (2025) 



Distribution of phosphorus in the blood. 

 By T. F. ZUCKER and MARGARET GUTMAN. 



[From the Department of Pathology, College of Physicians and 

 Surgeons, Columbia University, New York City.] 



It is well known that when blood is allowed to stand after it 

 has been drawn, its content of inorganic phosphate will gradually 

 increase to 1 mgm. or more above the figure which is obtained 

 when the determination is carried out immediately. This indi- 

 cates that the organic substances containing phosphoric acid 

 which occur in the blood, particularly in the red cells, in connec- 

 tion with which Greenwald has introduced the name "acid solu- 

 ble phosphorus" are slowly hydrolyzed to yield inorganic phos- 

 phate. This hydrolysis, however, is incomplete even when aided 

 by boiling with dilute acid. This finding would seem to indicate 

 that there must be two types of organic phosphoric acid combina- 

 tion in the blood, — one of which is easily hydrolyzed and the 

 other one not. To investigate this further, we have carried out 

 phosphorus determinations by Tisdall's micromethod on the 

 protein-free filtrate of blood, obtained by means of trichloracetic 

 acid. We determined the inorganic phosphate immediately and 

 again after boiling the filtrate for two hours. The total phos- 

 phorus in the filtrate (acid soluble phosphorus) was also deter- 

 mined. The results are shown in the accompanying chart. This 

 shows that a constant amount of phosphoric acid is split off by 

 boiling, approximately 10 mgm. of phosphorus being thus ob- 

 tained in human blood and 13 mgm. in rat's blood. This then 

 leaves for the organic hydrolysable phosphoric acid in the human 

 6-7 mg. and in the rat 5-7 mg. If we subtract the figure ob- 

 tained after boiling from the total acid soluble, we obtain the 

 figure representing the amount of phosphoric acid contained in 

 organic combination which is not hydrolysed under the condi- 

 tions stated. We have, therefore, evidence of three forms of 

 phosphoric acid which will pass into aqueous filtrates on coagu- 

 lation of the protein. 



It is evident that the above needs further substantiation. In 

 the first place, we must give evidence that the determination of 



