ORIGIN OF PHOSPHORUS COMPOUNDS IN HENS' EGGS 



285 



The high protein P content of the blood plasma of a lading hen has presumably 

 the same Viiologieal significaneo as the high phosphatide P content, namely a 

 reduction of the strain put on the protein resp. phosphat ide prochicing and eari_\ ing 

 system in the organism of laying hens. 



Phosphatide content of the liver 



We extracted the total phosphatide content of the livei- of a hen 28 hovirs 

 alter t ho administration of the labelliMl P, using the method described on page 277. 

 Since we were interested in seeing whether lecithin soluV)]e in ether shows the 

 same specific activity as the total phos{)ha1 ides we exlraded another part of 

 the liver tissue with ether alone. W'e found no marked difi'erence, as s(>en from 

 Tables 11 and 11a, which also ccntain data on the specific activity of inorganic 

 and acid soluble (other than inorganic) V of the liver. 



As seen from Table 11 the specific; ativity of the liver phosphatide P is 5(5% 

 of that of the inorganic P, from which it follows that about one half of the phos- 

 phatide molecules are labelled and thus formed after administral ion of the lab(>ll(>(i 



Table 11. — vSpkcific Activity of thk Livkr P 

 (Activity per mgni. P) 



Kiai-tioii 



Specific uclivitj 



Total phfjsphatides (ether-alcohol extract) 



Lecithin (ether extract ) 



Inorganic 



Acid soluble, other than inorganic 



0.0152 

 0.015S 

 0.0272 

 0.0224 



sodium phosphate. This result must, however, be interpreted with great caution. 

 As already mentioned on page 277 in the early stage of the experiment the specific 

 activity of P of the plasma is much higher than in the latter stages and the inorga- 

 nic P of the liver was also more active at the early stage. This change of the speci- 

 fic; activity with time would not affect our lesults if the specific activity of the 

 phosphatide P shovild decrease with time at the same rate as does that of the 

 inorganic P. That is, however, not the case. The phosphatide molecmles can mainly 

 • scape from the circulation at an appreciable rate into the yolk, while the indivi- 

 (kial inorganic P atoms present in the plasma can rapidly exchange with such 

 piesent, for example, in the skeleton, the latter being a much faster proc^ess in 

 view of the huge extent of the skeleton. Therefore, when drawinir conclusion 



Table ila — Percentagk of Labelled P Administkreu 

 Found in Plasma, CoRPrscLEs and Liver 



J LI 



yu. 



