568 G ASTRO-INTESTINAL ''AUTOINTOXICATION 



II. PRODUCTS OF NORMAL DIGESTION 



Proteoses and Peptones. — Under normal conditions, these are 

 broken uj) in the intestinal wall into the amino-acids, through the 

 agency of erepsin, and do not appear in the blood in appreciable 

 quantities. To be sure, certain authors claim to have found albumose 

 in nonnal blood, but if present the amounts are extremely minute. 

 In conditions in which ulceration or other lesions are present in the 

 gastro-intestinal tract it is possible to find small amounts of proteoses 

 in the urine, probably absorbed through the abnormal areas, but 

 not in quantities sufficient to account for any appreciable intoxication, 

 although proteoses are distinctly toxic. This last statement has been 

 much contested, because the difficulty of purifying proteoses ob- 

 tained from ordinary sources has left open the possibility that such 

 toxic effects as have been observed are due to contaminating sub- 

 stances, and not to the proteoses themselves. More recent work, how- 

 ever, particularly that of Underbill,- Gibson -^ and Zunz,^ seems to 

 have established affirmatively the toxicity of proteoses, whether from 

 animal or vegetable proteins. Besides the classical effect of inhibiting 

 the coagulation of the blood, the proteoses have a lymphagogue effect 

 (Ileidenhain),'* cause a marked febrile reaction,^' and in doses of some 

 size are fatal to experimental animals (rabbits being much less sus- 

 ceptible than dogs and many other animals). Locally they cause a 

 mild inflammatory reaction, which is followed by the appearance of 

 much connective-tissue formation.** Long continued injection of pro- 

 teoses does not produce visceral lesions."'"^ The careful studies of Zunz 

 show that intravenous injection of hetero-albumose, thio-albumose, 

 deutero-albumose and proto-albumose cause a rise in blood pressure, 

 but large doses may cause a fall in pressure ; the abiuret products of 



2Amer. Jour. Physiol., 1903 (9), ?A5; Jour. Biol. Chcni., 1015 (22), 443, 

 (literature) . 

 2a Philippine Jour. Sei., 1914 (9). 490. 



3 Arch, intcrnat. plivsiol., 1911 (73), 110. 



4 F5ee also Nolf, Arch, internat de Diysiol., 1906 (3). 343. 



5 Gibson finds that carefully purified proteoses liave but a slight. ])vrofrenio ef- 

 fect. (Philippine Jour. Sci./l913 (8), 475.) 



6 In a paper appearing in tlie Transactions of the Chicago Pathological Society, 

 1903 (5), 240, I published the observation that repeated injections of Witte's 

 "peptone" (which consists chiefly of proteoses) into rabbits led to tlie ]>roduction 

 of marked cirrhosis of the liver, and sujrgested the possil)ility that jiroteoses 

 escaping tlirougli a diseased gastr'c or intestinal wall into the blood might be 

 a factor in tlie production of cirrhos's in man. Subse()uent. observations, how- 

 ever, have shown tliat rei)eated injection of almost any foreign protein material 

 (e. g., emulsions of organs, foreign })lood. etc., used in immunization exjieriments) 

 will cause a similar cirrliosis in ral)bits, which animals, indeed, often spon- 

 taneously sliow this condition when apparently otherwise normal. "Peptone" in- 

 jections in dogs and guinea-pigs have failed to cause a similar cirrhosis, and lu'nce 

 the value of tliese and all other rabbit. exi)eriments on cirrliosis of the liver is 

 very questionable: however, the possibility of the correctness of the original con- 

 clusions still remains open. 



flaWoolley et al., Jour. Exp. Med., 1915 (22), 114. 



