676 URINE. 



Purine Bases (ALLOXURIC BASES) . The purine bases found in human 

 urine are xanthine, guanine, hypoxanthine, adenine, paraxanthine, heteroxan- 

 thine, episarkine, epiguanine, 1-methylxanthine, and carnine. The occurrence 

 of guanine and carnine (POUCHET) is, according to KRUGER and SALOMON, 1 

 not positively shown. The quantity of these bodies in the urine is 

 extremely small and varies in different individuals. FLATOW and REIT- 

 ZENSTEIN 2 found 15.6-^5.1 milligrams in the urine voided during twenty- 

 four hours. The quantity of alloxuric bases in the urine is regularly 

 increased after feeding with nucleins or food rich in nucleins, and after an 

 abundant destruction of leucocytes. The quantity is especially increased 

 in leucaemia. We have a number of observations on the elimination of 

 these bodies in different diseases, but they are hardly trustworthy on 

 account of the inaccuracy of the methods used in the determinations. 

 It must also be remarked that the three purine bases, heteroxanthine, 

 paraxanthine, and 1-methylxanthine, which form the chief mass of the 

 purine bases of the urine, are derived, according to the investigations 

 of ALBANESE, BONDZYNSKI and GOTTLIEB, E. FISCHER, M. KRUGER 

 and G. SALOMON, and SCHMIDT and KOTAKE 3 from the theobromine, 

 caffeine, and theophylline which occur in the food. With the purine 

 bases we must also differentiate between those of endogenous and those 

 of exogenous origin, 4 and the same factors apply as for the uric acid, 

 viz., the endogenous. purine formation represents a value which is some- 

 what variable for different individuals and relatively constant for the 

 same individual. According to SivEN, 5 with purine-fiee diet the elimina- 

 tion of purines is lowest at night and highest in the morning hours. Rest 

 and work do not show any positive difference. As the four true nuclein 

 bases and carnine have been treated in Chapters III and XI, it only 

 remains to describe the special urinary purine bodies. 



HN CO 

 Heteroxanthine, C 6 HeN 4 02, 7-monomethylxanthine, OC C.N.CH 3 , was first 



1 Zeitschr. f. physiol. Chem., 24; Pouchet, " Contributions & la connaissance des 

 matieres extractives de 1'urine." These Paris, 1880. Cited from Huppert-Neubauer, 

 333 and 335. 



2 Deutsch. med. Wochenschr., 1897. 



3 Albanese, Ber. d. d. chem. Gesellsch., 32; Arch. f. exp. Path. u. Pharm., 35; 

 Bondzynski and Gottlieb, ibid., 36, and Ber. d. deutsch. chem., Gesellsch., 28; E. 

 Fischer, ibid., 30, 2405; Kriiger and Salomon, Zeitschr. f. physiol. Chem., 26; Kriiger 

 and Schmidt, Ber. d. d. chem. Gesellsch., 32, and Arch. f. exp. Path. u. Pharm., 45; 

 Kotake, Zeitschr. f. physiol. Chem., 57. 



4 See Burian and Schur, footnote 1, page 667, and Kaufmann and Mohr, Deutsch. 

 Arch. f. klin. Med., 74. 



5 Skand. Arch. f. Physiol., 18. 



