592 GASTRO-INTESTINAL "AUTOINTOXICATION" 



such (Garrod). This would amount to some five grams per day, 

 whereas the average excretion is only about 0.3-0.5 gram, and sul- 

 phates and other neutral sulphur compounds are always present in 

 the urine. In no condition other than cj^stinuria have putrescine and 

 cadaverine been found in quantities which could be detected by ordi- 

 nary methods in 24-hour specimens; they may also be found in the 

 feces of cystinurics, where cystine is never found. In the urine their 

 presence is inconstant, and the amounts are at best very small. Leu- 

 cine and tyrosine are found much less often than the diamines; lysine, 

 has been found in one case,^^ which supports the view that cadaverine 

 and putrescine come from the diamino-acids of the protein molecule 

 by metabolism rather than by putrefaction. 



B. Products of Fermentation of Carbohydrates 



These include practically all the members of the fatty acid series, from formic 

 acid to valerianic acid; and the oxy-acids, lactic, succinic, and oxybutyric; also, 

 oxalic acid, acetone, ethyl alcohol, and the following gases: CO2, CH^, H2. For the 

 most part, the various organic acids are absorbed through the intestinal walls, and 

 are oxidized completely in the tissues without causing any harm whatever. The 

 possibility that acid intoxication may be produced in this way has been suggested, 

 but it is generally believed that this does not occur, except possibly in infants. 

 Lactic and butyric^^ acids are formed particularly in gastric fermentations in persons 

 with deficient hydrochloric acid, motor insufficiency, or organic obstruction. Most 

 of the disturbances observed in these conditions seem to be due to distention of the 

 stomach with gas, chiefly CO2, which is formed during the fermentation. It is 

 possible, however, that the organic acids exercise some irritant effects on the mucous 

 membrane; and they may also cause diarrhea, lactic and acetic acid often being 

 present in diarrheal discharges due to excessive feeding with carbohydrates (Her- 

 ter). 



These acids or their salts do not appear in the urine, unless possibly as minute 

 traces, except the oxalic acid. Minute quantities (0.02 gm. per day) of this sub- 

 stance are present in normal urine, but larger quantities {oxaluria) seem to depend 

 either upon the taking of food containing much oxalic acid (rhubarb, spinach, etc.) 

 or upon excessive gastric fermentation of carbohydrates (Baldwin),^'' and perhaps 

 upon excessive destruction of purines, from which oxalic acid may be derived. 

 Of the amino-acids it is presumably the diatomic acids, glutamic and aspartic, 

 which yield oxalic acid (Jastrowitz).^^ Others, however, do not admit that any 

 appreciable amount of oxalic acid is derived from proteins. ^^ Probably the small 

 quantities of oxalic acid thus formed do not cause toxic effects, and are im- 

 portant chiefly as causing urinary concretions of calcium oxalate, although there is 

 evidence that long-continued excretion of oxalic acid may cause renal lesions. 

 (See also consideration of oxalate calculi, Chap, xvii.) 



C. Products of the Decomposition of Fats 



These differ but little in nature from the products of carbohydrate fermenta- 

 tion, the large fatty acid molecules being broken down to smaller ones. In infants 

 these fatty acids have been believed to be a cause of acid intoxication and aceto- 

 nuria," but probably they are seldom, if ever, of pathological importance. It is 



"- Ackcrmannand Kutscher, Zeit. f. Biol., 1911 (57), 3.'55. 



" Coleman (Ann. Inst. Pasteur, 1915 (29), 139) attempts to incriminate butyric 

 acid in the i)roduction of arteriosclerosis, while Oswald Loeb believed lactic acid 

 to ha important, a view which could not be altogether supported by Denny and 

 Frothingham, .Jour. Mod. Res., 1914 (31), 277. 



9" Jour. Exp. Med., 1900 (5), 27. 



" Biochem. Zeit., 1910 (28), 34. 



»8 Wcgrzynowski, Zeit. physiol. Chem., 1913 (83), 112. 



07 Meyer and Langstein, .Jahrb. f. Kinderheilk., 1900 (03), 30. 



