560 ABNORMALITIES IN METABOLISM 



apparent that not much if any urinary acetoacetic acid is derived from 

 this source. 



As long as a normal individual is burning at least one molecule of 

 carbohydrate to three of higher fatty acids the urine is free from more 

 than traces of these three "acetone bodies, "'^- but when for any reason 

 daily oxidation of carbohydrates falls below this minimum the two the 

 acids appear, combined largely with ammonia, but partly with mineral 

 bases. Fats burn in the fire of the carbohydrates, and, as Wood- 

 yatt*^^ puts it, when the proportion of fat is too great for the fire 

 it "smokes" with unburnt fats and acetone bodies. Normally but 2 

 to 5 per cent, of the nitrogen of the urine is in the form of ammonia, 

 but in diabetic acidosis the proportion may reach from 10 to 25 per 

 cent., the proportion of urea being correspondingly reduced.^'* 



The presence of large quantities of these acids in the urine presages 

 coma, during which the amount of oxybutyric acid often reaches 15-20 

 grams per day, and has been known to reach 150 grams (Kiilz claimed 

 to have found 226 grams). Diacetic acid appears in relatively small 

 amounts, rarely exceeding 10 per cent, of the total organic acids of 

 the urine ;^^ as a rule, when any one of the three acetone bodies is 

 present in large amounts, there is an abundance of each of the others. 

 Kenneway'''^ confirms Neubauer's statement that oxybutyric acid is 

 rather constantly from 60 to 80 per cent, of the total acetone bodies 

 excreted in the urine. In the internal organs the acetone bodies may 

 also be detected, especially in the liver." In normal blood Marriott 

 found less than 4 mg, of oxybutyric acid, and 1.5 mg. of acetone and 

 aceto-acetic acid together, per 100 c.c; but in diabetic coma the 

 figures rose as high as 45 mg. and 28 mg. respectively for each fraction, 

 the amount in the blood not corresponding to the urinary excretion, ^^ or 

 to the bicarbonate content of the blood. "^^ Associated with acidosis is 

 usually an increase in the blood lipins.'^" 



Relation of Acidosis to Diabetic Coma. — There seems to be 

 httle room for doubt that the typical diabetic coma with "air hunger" 



^^JVeeder and Johnson (Amer.''Jour. Dis. Chil., 1916 (11), 291) give as the nor- 

 mal daily average excretion 32 mg. of ketones (diacetic acid and acetone) and 38 

 mg. oxybutyric acid. The old statement that acetone appears in advance of tlie 

 two acids is incorrect, the error being due to faulty methods (See Howhind and 

 Marriott, Amer. Jour. Dis. Chil., 1916 (12), 459). Concerning normal occurrence 

 of acetone in blood and tissues, see Halpern and Landau, Zeit. exp. Path. u. Ther., 

 1906 (3), 466. 



63 Jour. Amer. Med. Assoc, 1916 (66), 1910. 



"According to Edie and Whitley (Biochemical Jour., 1906 (1), 11), adminis- 

 tration of excessive amounts of alkali causes, conversely, elimination of increased 

 amounts of organic acids. 



6^ Folin says that perfectly fresh diabetic urine does not contain any acetone, 

 that which is commonly found being derived from diacetic acid which rapidly 

 decomposes into acetone. 



"" Biochem. Jour., 1913 (8), 355. 



" Sassa, Biochem. Zeit., 1914 (59), 362. 



«« Marriott, Jour. Biol. Chcm., 1914 (18), 507. 



^Titz, Trans. Assoc. Amer. Phys., 1917 (32), 155. 



'"> Gray, Boat. Med. Surg. Jour., 1917 (178), 16-156. 



