472 G ASTRO-INTESTINAL "AUTOINTOXICATION" 



most available index of the amount of putrefaction that is occur- 

 ring in the intestines. The greatest quantities are found when 

 intestinal putrefaction is marked, especially in intestinal obstruc- 

 tion involving the small intestine ; obstruction of the large 

 intestine, as JafFe first demonstrated, does not cause marked 

 indicanuria unless the stagnation involves the ileum, as it may 

 in the latter stages of obstruction. There can be no question that 

 the indican of the urine is derived, at least in part, from the indol 

 formed in the intestine, for administration of indol by mouth to 

 either animals or man causes a considerable increase in the 

 indican present in the urine ; however, but 40 to 60 per cent, 

 can be recovered in this way, the rest apparently being oxidized 

 to other compounds, part of which may also appear in the urine. 1 

 Whether part of the urinary indican is derived from tryptophan 

 liberated during intracellular proteid metabolism, and not from 

 intestinal putrefaction, has long been a disputed point among 

 physiological chemists. 2 The demonstration by Ellinger and 

 Gentzen 3 that tryptophan, when fed or injected subcutaneously 

 causes no increase in urinary indican, whereas its injection into 

 the cecum causes much indicanuria, would indicate that indol is 

 formed from tryptophan only through putrefaction, and not in 

 cellular metabolism. Other experiments support the same view. 4 

 However, it is possible that part of the indican present in the 

 urine during conditions associated with gangrene, putrid cancers, 

 putrid placentas, or putrid purulent exudates may be derived 

 from these decomposing materials. 



Probably the chief agent in the formation of indol in the 

 intestines and in putrid tissues is the colon bacillus, which, as 

 is well known, produces indol in ordinary culture-media. 



Toxicity of Indol. Although the toxicity of indol seems to 

 be relatively slight, and this toxicity is further reduced by the 

 conversion of indol into indoxyl and indican, yet Herter 5 

 found that administration to healthy men of indol in quantities 

 of 0.025 to 2 grams per day caused frontal headache, irritability, 

 insomnia, and confusion ; the continued absorption of enough 

 iudol to cause a constant strong reaction for indican in the urine 

 is sufficient to cause neurasthenic symptoms. Lee 6 has also 



1 If gelatin is substituted for proteids in the dietary, indican is not excreted, 

 because gelatin does not contain tryptophan (Underbill, Amer. Jour. Physiol., 

 1904 (12), 176). 



2 Literature by Gerhardt, Ergeb. der Physiol., 1904 (III, Abt. 1), 131. 

 3 Hofmeister's Beitr., 1903 (4), 171. 



4 See Scholz, Zeit. physiol. Chem., 1903 (38), 513; Underbill, loc.cit. 



5 New York Med. Jour., 1898 (68), 89. 



6 Jour. Amer. Med. Assoc., 1906 (46), 1499. 



