METABOLISM 45 



' goutiness ' which has hitherto prevailed in clinical 

 medicine. 



Uric acid belongs chemically to the group of bodies 

 called 'purins,' which possess a common nucleus, the 

 purin nucleus, or ring, having the following formula : 



N=CH 

 HC C-NHs 



>CH 



N-C-N * 



Uric acid is trioxypurin : 



HN-CO H-N-CO 

 II II 



OC\C-NH X oc c-rrH. 



30 I co 



It is not very long since it was believed that uric acid 

 resulted from the breaking down of any protein in the 

 body, and as a corollary of this it was taught that in 

 gout, in which there is an excess of uric acid in the 

 body, any protein food is bad for the patient, and he 

 should consume as little of it as possible. It is now 

 known that the breaking down of proteins as such does 

 not give rise to uric acid, but that the latter is derived 

 from three possible sources. 



1. From Purin Bodies contained in the Food. This is 

 called * exogenous ' uric acid. The foods which contain 

 most purin are flesh foods and the internal organs of 

 animals (e.g., liver and sweetbreads), peas, beans and 

 lentils, oatmeal, asparagus, tea and coffee. 



Of the purins taken in with the food part are destroyed 

 in the body probably in the liver with the production 



