CIRCULATIOX OF PHOsPHOliUS I.\ THE HlOG 401 



3-P content of the red corpuscles 



As seen in Table 22, a very slow interaction was found to take place 

 l)etween the plasma P and the corpuscle P present in the nucleated 

 corpuscles of the frog. 



Summary 



The rate of absorption of phosphate injected into the lymph saek of the frog 

 was stviclied using radiophospliorus as an indicator. The niaxinuini amount of 

 labelled phosphate present in the circulation after subcutaneous injcMjtion at any 

 moment was found to be 3 to 4 per cent of the amount administered, thus a 

 similar value as fountl in the case of mammalia. 



While at 2° after the lapse of 1 to 3 weeks 1 gin bone tissue contained about 

 lo times as many labelled P atoms as 1 gm muscle tissue, the corresponding 

 ratio was found to be but 3 at 22°, showing that the temperature coefficient of 

 the penetration of labelled phosphate into the muscle cells followed by incorpora- 

 tion of labelled P into the phosphorus compounds of the muscle tissue is much 

 larger than the temperature coefficient of the formation of labelled bone apatite 

 crystals. 



The amount of labelled phosphate excreted by the kidneys and the amount 

 of labelled phosphate taken up by the frog kept in physiological sodium chloride 

 solution containing labelled phosphate were investigated. 



The rate of renewal of various acid soluble P compounds extracted fi-om the 

 gastrocnemius of the frog was determined b\' comparing the specific activity 

 of the inorganic P extracted from the muscle with the specific activity of the 

 phosphorus split off from various organic compounds of the muscle tissue. Creatine- 

 phosphoric! acid molecules, adenosintriphosphoric acid molecules, and also hexose- 

 monophosphate molecules were found to be renewed at an appreciable rate even 

 at 0". The rate of renewal was found to increase with decreasing chemical stabihty 

 of the compound and with increasing temperature. 



The rate of interaction of the plasma phosphate with the phosphate of the 

 mviscle cells was found to be very much lower than the rate of interaction of the 

 free cellular phosphate with the phosphate of .several organic phosphorus com- 

 pounds. 



The rate of penetration of labelled phosphate into the liver celLs is much faster 

 than the rate of penetration into the muscle cells. The rate of interchange of plasma 

 phosphate and the phosphate of the corpuscles was found to be fairly low. 



2G Hevesv 



