Distribution of Inorganic Phosphate of Blood. 169 



fraction after alkaline hydrolysis. It is not an organic base of 

 the type described as occurring in cod-liver oil. It is not choles- 

 terol, but similar to cholesterol in its solubilities. The suggestion 

 is made that it may be a sterol related to cholesterol or a choles- 

 terol derivative. The fatty acids of cod-liver oil are entirely 

 inactive in curing rickets. 



78 (1825) 



The distribution of inorganic phosphate of the blood between 



plasma and cells. 



By T. F. ZUCKER and MARGARET B. GUTMAN. 



[From the Department of Pathology, College of Physicians and 

 Surgeons, Columbia University, New York City.] 



Since Greenwald's work on the organic acid soluble phosphorus 

 our knowledge of the various phosphorus compounds in the blood 

 is steadily increasing and acquiring significance. The determi- 

 nation of the inorganic blood phosphate, however, has been very 

 questionable, particularly in corpuscles, due to the ease with which 

 the organic acid soluble phosphate is hydrolyzed. Any method 

 which requires considerable time or in which the phosphate has to 

 be precipitated, or in which the red cells are washed or otherwise 

 manipulated, comes very gravely under suspicion of having allowed 

 a significant amount of hydrolysis to take place. 



When working only with plasma these precautions are not so 

 necessary. Bloor's 1 figures for inorganic phosphate in the cor- 

 puscles are admittedly high. A method very well suited to esti- 

 mation of inorganic phosphate is that of Bell and Doisy 2 in 

 which the color of the blue reduction product of phosphomolybdic 

 acid is measured as in Folin's uric acid and phenol determintion, 

 the limiting factor, however, being the phosphate. 



Our results have been briefly as follows : 



When working rapidly with the Bell and Doisy method, the 

 inorganic phosphate in the plasma and the whole blood is the same 

 within the limit of error of the method. The few exceptions to 

 this were traced to improper handling of the blood or too long a 

 time elapsing before the determination. Even here the whole 



1 Bloor, Jour. Biol. Chem., 1918, xxxvi, 49. 



2 Bell and Doisy, Jour. Biol. Chem., 1920, xliv, 55. 



