144 Society for Experimental Biology and Medicine. 



99 (242) 



The presence of allantoin in the urine of the dog during 



starvation. 



By FRANK P. UNDERHILL. 



\_From the Sheffield Laboratory of Physiological Chemistry, Yale 



University.} 



The presence of allantoin in the urine, especially of carnivora, 

 has afforded the impetus for a large number of investigations. A 

 great deal of the interest manifested in this substance has been 

 excited by its close chemical relationship to uric acid and the pos- 

 sible significance it may bear to uric acid metabolism. The con- 

 sensus of opinion seems to indicate that the appearance of allantoin 

 in the urine of the dog at least depends in large measure upon the 

 type of proteid ingested. Thus, after feeding tissues or organs 

 rich in nucleoproteid, or nucleoproteid itself, the quantity of 

 allantoin eliminated is greatly increased. It is to the nuclein-con- 

 taining radical of the proteid that the origin of allantoin has been 

 ascribed. Other observations have shown that allantoin may 

 appear in the urine under various pathological conditions involving 

 destruction of nuclear material. 



During the progress of an investigation upon intermediary 

 metabolism it became necessary to subject the experimental animals 

 to periods of starvation lasting from ten days to two weeks. 

 From the urine of these dogs allantoin separated spontaneously 

 in pure white crystals and the presence of this substance in the 

 urine was constant. So far as I am aware, the presence of 

 allantoin in the urine during starvation has not been recorded 

 hitherto. This observation makes it probable that allantoin is a 

 constant constituent of the urine of the dog. 



