INTERACTION OK PLASMA PHOSPHATE WITH THE PHOSPHOBUS ('OMI'OTNDS 4715 



corpuscle membrane to phosphate ions is to introduce sodium phosphate 

 into the plasma and to investigate if and to what extent the phosphate 

 and phosphoric ester content of the corpuscles is increased. By using 

 this line of attack Halpern found that at 3° inorganic P does not 

 enter or leave the blood cell to any appreciable extent in the course 

 of 9 hours. Above 23° a very slow, at 37° an apprecialile penetration 

 of the additional phosphate into the corpuscles was observed. 



A very convenient way of the study of exchange between phosphorus 

 components present in the plasma and the corpuscles is opened by the 

 application of labeHed (radioactive) phosphate. By introducing active 

 sodium phosphate of negligible weight into the plasma, all the phosphate 

 ions present in the latter get labelled and, if after the lapse of some time 

 radioactive phosphorus compounds are found to be present in the cor- 

 puscles, we can conclude that these penetrated during the time in question 

 from Ihe plasma into the corpuscles. We carried out experiments both 

 in vivo and in vitro, introducing active sodium phosphate into the plasma 

 and investigating, after the lapse of a few hours, the activity and the 

 concentration of the inorganic phosphate and also of the phosphoric 

 esters present in plasma and corpuscles. In other cases active hexo- 

 semonophosphate was introduced into the plasma and the activity and 

 concentration of the above mentioned P compounds were measured. 

 In view of the very slow rate of the formation of labelled "non-acid 

 soluble" phosphorus-compounds present in the blood (phosphatides and 

 phosphorus containing proteins) ascertained in our former work^^) we left 

 those substances out of consideration in this investigation. Some of the 

 acid-soluble phosphorus compounds, of W'hich a great variety occurs in 

 the corpuscles, were found to be labelled to a large extent after the lapse 

 of a short time. The problem which first occurs is whether the labelled 

 organic phosphorus compounds (phosphorus esters and others which we 

 will in what follows denote as "phosphorus ester") are formed within 

 the corpuscles from active inorganic phosphate or whether active esters 

 diffuse from the plasma into the corpuscles. As we will see later, the 

 labelled esters found in the corpuscles are, at least to a large exteni 

 synthesized within the corpuscles. 



As to the nature of phosphoric esters present in the corpuscles, the 

 presence of various compounds has been recorded, such as adenosintri- 

 phosphate, hexosephosphate, triosephosphate, mono- and diphospho- 

 glycerate, glycerophosphate, and phosphopyruvate. The composition of 

 the corpuscles of different animals was found to be markedly different ; 

 while the corpuscles the blood of sheep contain, (2) for example, 80% of 

 esters which are hydrolysed by boiling 1 n. HCl within 3 hours, the 



WL. Hahn and G. Hevesy, Mem. Carlsherg Lab. 22, 188 (1938). 

 (2>H. V. EuLER and K. M. Brandt, Z. phy-nol. Chem. 240, 2 IT, (1030). 



