THE METABOLISM IN GOUT 425 



the uric acid was as high as one finds in a normal person on a purin free 

 diet. 



It has been shown that the ingestion of amino-acids increases the endog- 

 enous uric acid output. As no digestive activity is necessary for their 

 utilization the rise in uric acid cannot be attributed to the work of the di- 

 gestive glands (Lewis, Dunn and Doisy). As amino-acids probably stimu- 

 late cellular activity to marked degree (Lusk(b) (d)), the rise of uric acid 

 may be attributed to a direct stimulation of nuclear metabolism in the body 

 by amino-acids or their catabolic products, and the rise in uric acid ob- 

 served by MareS occurring during the first hours of digestion may be at- 

 tributed in the light of this work on amino-acids with as much reason 

 to stimulation of cellular activity by products absorbed from stomach and 

 intestine, as to the activity of the digestive organs. 



Uric Acid in the Blood in Health. A small amount of free uric acid 

 is always found in the blood. In 1913 Folin and Denis (c) published an 

 accurate colorimetric method for its determination. They found amounts 

 of uric acid ranging from 0.7 to 3.7 mg. per 100 c.c. of blood; Myers and 

 Fine(a) using Benedict's modification of Folin's method 1.0 to 2.0 mg. ; 

 Gettler and Baker in a series of thirty normal cases 1.0 to 3.5 mg. 



According to the old, but still generally accepted, view the uric acid in 

 the blood is in the form of monosodium urate. Pure uric acid is about 

 twenty times more soluble in serum than is monosodium urate (Eob- 

 erts(fr), Beohhold and Ziegler(ct)). 



It is held by some that sodium urate in the blood is in colloid form 

 (Schade(&)(c) (a) and Boden(c), Bechhold and Ziegler). Other investi- 

 gators deny the existence of a colloid solution of uric acid or of the urates 

 in the blood (Gudzent(d), Kohler(a), Lichtwitz ((/)). 



The plasma and blood corpuscles contain varying proportions of uric 

 acid (Steinitz(6), Bornstein (a) and Griesbach(a)). Sometimes there is 

 more uric acid found in the serum, sometimes more in the corpuscles. In 

 only two cases examined by Bornstein and Griesbach(a) was the uric acid 

 found exclusively in the corpuscles. The cause of this difference in distri- 

 bution is unknown. Analogies are seen in the distribution of blood sugar 

 Steep (a), Loeb(&)). 



In ox blood S. Benedict (a) found the uric acid exclusively in the cor- 

 puscles while in chicken blood it is almost all in the serum. 



In 1915 S. Benedict (a) discovered that uric acid in ox-blood exists 

 chiefly in a combined form. In one specimen he found .56 mg. of uric acid. 

 After boiling with HOI the same blood yielded 5.87 mg. of uric acid. 

 Benedict has recently isolated this combined uric acid in a pure crystal- 

 line state. It is a nucleosid in which the carbohydrate is pentose, and 

 hence, a decomposition product of plant nucleic acid. 



Bornstein and Griesbach(5) have found combined uric acid in the ma- 

 jority of specimens of human blood they have examined. The amount 



