Originally published in D. Kgl. Danske V idenskahernes Selskab. Biologiske 



Meddelelser. 14, 3 (1939). 



55. EXCRETION OF PHOSPHORUS 



G. Hevesy, L. Hahn, O. Rebbe 



From the Institut of Theoretical Physics, University of Copenhagen 



Because of the great importance of phosphorus in the formation of 

 bones and the functional significance of a great variety of phosphorus 

 compounds the balance of phosphorus intake and excretion has been 

 investigated in numerous cases. A vast literature on this subject is 

 available in which often also the route of secretion is considered, that 

 is, the ratio in which the excreted phosphorus is to be found in the urine 

 and faeces of the human subject or animal investigated. What percentage 

 of the phosphorus excreted in the faeces is due to non-absorbed material 

 and how much to phosphorus, originating from the body proper is, 

 however, not yet known. Neither is any statement to be found on the 

 fate of the individual phosphorus atoms, for example the phosphorus 

 taken up with the food on one certain day. By using radioactive phos- 

 phorus as indicator we can follow the circulation of the phosphorus 

 taken up at a certain date with food, the route it takes, and the rate at 

 which it leaves the body. Some information on this subject has already 

 been given. (i) In this paper we are communicating the results of investi- 

 gations in which the excreta of human subjects, produced in the course 

 of few months, were investigated both by radioactive and by chemical 

 methods. Data are also given on the phosphorus excretion of rats. 



GENERAL EXPERIENCE AS TO PHOSPHORUS EXCRETION 



Ingested phosphates are excreted partly in the faeces and partly in 

 the urine, the ordinary distribution in adult man being about two thirds 

 in the urine and one third in the faeces. Conditions that diminish the 

 solubility or promote the precipitation of phosphorus in the intestinal 

 canal, tend to reduce the amount excreted in the urine and to increase 



^1^ O. Chiewitz and G. Hevesy, Nature 136, 754 (1935); Kgl. Danske Vidensk, 

 Selsk. Biol. Medd. 13, 9 (1937); L. Hahn, G. Hevesy and E. Lundsgaabd, 

 Biochem. J. 31, 1706 (1937); W. E. Cohn and O. M. Gbeenberg, J. Biol. Chem. 

 123, 185 (1938). 



