CHAPTER XXIII 



URIC-ACID METABOLISM AND GOUTi 



These subjects have been the object of such a prodigious amount 

 of research that it is far beyond the scope of this work to review the 

 history and the details of the investigations. Such a review is also 

 particularly unnecessary, since it can be found in the works on phys- 

 iological chemistry and various treatises on metabohsm. Conse- 

 quently the attempt will be made in this chapter merely to give, as 

 briefly as possible, the views now most generally accepted concerning 

 the nature and metabolism of uric acid, and its relation to patho- 

 logical processes. For the historical discussion, indicating by what 

 devious steps we have reached our present understanding concerning 

 this long-disputed subject, the reader is referred to the articles men- 

 tioned below, upon which I have drawn freely. A particularly clear 

 summary of the subject is given by Walter Jones in his monograph on 

 nucleic acids. ^ 



THE CHEMISTRY OF URIC ACID 



It is the very great service of Emil Fischer to have shown us the 

 structure of the uric-acid molecule, the empirical formula of which, 

 C5H4N4O3, had long been known. He demonstrated that it is a mem- 

 ber of a group of substances, which are all characterized bj' being 

 built up about a certain nucleus, C5N4. As the simplest member of 

 the group is a synthetically formed body, purine, the nucleus is called 

 the '^-purine nucleus." The structural relations of the better-known 

 ^'purine bodies" to this purine nucleus and to each other are clearly 

 shown by their structural formulae, as given below: 



The atoms in the "purine nucleus" are arranged as follows: 

 N(i)-C(6) 



C(2) - C(5) -N(7) 

 N(3)-C(4)-N(9) 



To each atom has been given a number, as shown, for the purpose of 

 facilitating reference to the location of various atoms and groups 



^ Complete reviews are given by F. H. McCrudden, "Uric Acid," New York, 

 1906; Wiener, Ergebnisse der Physiol., 1902 (1), 555; ibid., 1903 (2), 377; Burian 

 and Schur, Pfliiger's Arch., 1900 (80), 241; 1901 (87), 239; Schittenhelni, Handb. d. 

 Biochem., 1910, IV d), 489; Brugsch and Schittenhelni, "Die Nukleinstoffwoclisol 

 und seine Storungen," Jena, 1910; Walter Jones, "Nucleic Acids," Monographs on 

 Biochemistry, 1914. An excellent summary of recent work is given by Benedict, 

 Jour. Lab. Clin. Med., 1916 (2), 1. 



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