DISTRIBUTION OF URIC ACID (iiio 



measure that an actual iMtoxifati(jn witli uric acid pn^hably never 

 occurs. 



The amount present in tlie urine nuiy be very considerably in- 

 creased by eating food ricli in jnirines, of wliich sweet-breads, liver, 

 and kidney are the best examples; and also coffee with its caffeine 

 (trimethyl purine), may give rise to a little uric acid, although the 

 methylated purines seem to be destroyed in large part, or eliminated 

 as something else than uric acid. Large quantities of meat will also 

 increase the uric acid, because of the free purines contained in muscle; 

 and even a diet rich in proteins free from purine will also increase the 

 uric acid excretion over that of a low protein diet.-* On a purine-free 

 diet the excretion of endogenous uric acid is increased by increasing 

 even the non-protein calories (Host).-^ However, the amount of uric 

 acid in the blood is not correspondingly raised by purine-rich diets, ^^ 

 this being regulated by the binding function of the tissues and by excre- 

 tion through the kidneys.-^ According to Folin and Denis-^ human 

 blood normally contains 1.5-2.5 mgs. uric acid in 100 c.c, and the 

 amount bears no fixed relation to the amount of urea and total non- 

 protein nitrogen of the blood. ^° All the uric acid in human blood 

 seems to exist free as monosodium urate, and not in a colloidal state 

 (Gudzent).^^ Any difficulty in renal ehmination is usually accom- 

 panied by an increase in the amount of uric acid in the blood, in ure- 

 mia as much as 15 to 20 mg. being sometimes found per 100 c.c.'- 

 In early interstitial nephritis there may be 4 to 8 mg. of uric acid per 

 100 c.c. blood without a corresponding increase in urea and creatinine, 

 W'hich suggests that uric acid may be less easily excreted by the dis- 

 eased kidney than the other chief nitrogenous constituents of the 

 urine. 



In normal individuals there seems to be httle uric acid present in 

 the tissues. Bj^ using Folin's method, Fine^^ found that various tis- 

 sues contain quantities comparable to that in the blood of the same 

 person, whether this is normal or increased in amount. Ordinarily 

 these quantities are not sufficient to permit readily of isolation of the 

 uric acid in a pure state, but in the tissues of a young woman who died 

 after complete suppression of urine for nine days following poisoning 

 with HgCl2, I found considerable amounts. ^^ Whenever much de- 



=« Taylor and Rose, Jour. Biol. Chem., 1914 (18), 519; Lewis and Doisv, ibid., 

 1918 (36), 1. 



2" See Denis, Jour. Biol. Chem., 1915 (23), 147. 



-^ Stocker found uric acid in saliva, increased in all conditions associated 

 with uricemia (Inaug. Dissert., Zurich, 1913). 



"Jour. Biol. Chem., 1913 (14), 29; Arch. Int. Med., 1915 (16), 33. 



^0 In infants the amount is sUghtlv lower, about 1.3 to 1.7 mg. Liefraann, 

 Zeit. Kinderheilk., 1915 (12), 227. 



" Zeit. klin. Med.. 1916 (82), 409. 



32 See FoUn and Denis, Arch. Int. Med., 1915 (16), 33; Meyers and Fine, 

 ihid., 1916 (17), 570; Baumann et al, ibid., 1919 (24), 70. 



" Jour. Biol. Chem., 1915 (23), 473. 



" Jour. Biol. Chem., 1916 (26), 319. 



