THE METABOLISM 



GOUT 



421 



tissues is possibly destroyed. At any rate those that hold the view that 

 uricolysis does not occur cannot support it now as formerly by the results 

 obtained by introducing uric acid parenterally. Furthermore^ Bornstein 

 and Griesbach(a) show that the uric acid in the blood often decreases if 

 kept at body temperature in sterile flasks for a few hours after its with- 

 drawal from the body. Taking the evidence at present available it seems 

 to the writer that while uricolysis probably does not occur in the human 

 body, its existence has not been disproved. 



Before concluding this section on the formation of uric acid from 

 nucleic acid mention should be made of the fundamental observations 'upon 

 which present knowledge is based. Horbaczewski(a) was the first to bring 

 experimental proof of the formation of purin bases and uric acid from 

 nucleic acid. By digesting the ox spleen, rich in nucleic acid in the form 

 of nucleoproteins, with blood he obtained uric acid when oxygen was con- 

 ducted through the mixture of spleen pulp, and xanthin and hypoxanthin 

 when air was not introduced. He had no, 'conception of the true nature of 

 this formation of uric acid from the purin bases, but thought it was due 

 to putrefaction. Wiener and also 'Spitzer proved that both xanthin and 

 hypoxanthin are oxidized to uric acid by ferment action and Spitzer also 

 discovered that xanthin-oxidase is confined to the liver and spleen. , 



Synthesis of Nucleic Acid and Uric Acid 



Miescher who had discovered nuclein in his chemical study of pus 

 cells found that the head of the spermatozoa of the Rhine salmon was free 

 from protein and consisted of the same chemical body he had found in pus. 

 It gave the reactions for protein, but contained phosphorus and was re- 

 sistant to gastric digestion. This was nuclein. In ascending the Rhine 

 the fish took no food. Spermatic fluid made up of spermatozoa in dilute 

 salt solution is formed in great quantity at the expense of the muscle pro- 

 tein. This was a clear demonstration of the formation of nucleic acid 

 from protein. Synthesis of nucleic acid from protein has been shown 

 to occur in the developing hen's egg (Kossel), in young rabbits (Burian 

 and Schur(o.)), and in the adult Dalmatian dog (S. R. Benedict(&)). It 

 is quite likely that the amino-acids arginiri and histidin may serve as purin 

 precursors (Ackroyd and Hopkins). The synthesis of uric acid from am- 

 monium lactate and urea occurs in birds according to Minkowski(fr). 

 Kowalewski and Salaskin presented evidence that ammonium lactate was 

 converted into uric acid by perfusion through an isolated goose liver. This 

 work has been generally accepted, but Friedmanri and Mandel and also 

 Glaeserow maintain that convincing proof is lacking that ammonium lac- 

 tate is converted into uric acid in the liver of birds. Many attempts have 

 been made to prove fie synthetic formation of uric acid in mammals. 



