ICTERUS 409 



It is difficult to decide how much of the profound intoxica- 

 tion that is sometimes present in icterus ("cholemia" and 

 " icterus gravis ") to ascribe to the reabsorbed bile, for fre- 

 quently there is an accompanying infection, and even if there 

 is no infection the impairment of liver function by the obstruc- 

 tion to bile outflow must also be reckoned with. The liver is 

 not only the great destroyer of toxic substances absorbed from 

 the alimentary canal, but it is also an important seat of nitrog- 

 enous metabolism, interference with which may lead to ac- 

 cumulation of many toxic nitrogenous substances in the blood. 1 

 The long duration of severe icterus in some cases of occlusion 

 of the bile-ducts, with relatively slight evidences of intoxication, 

 would seem to indicate, however, that on the whole the bile is 

 not so much responsible for the intoxication observed in icterus 

 as are the associated conditions. On the other hand, in not a 

 few instances it has been observed that escape of large quanti- 

 ties of bile into the peritoneal cavity may be followed by symp- 

 toms similar to those of icterus gravis ; in these cases only the 

 bile can be held responsible for the intoxication. 2 



The Pigmentation in Icterus. Living tissues have 

 but a slight tendency to take up bile-pigments, much of the 

 tissue-staining observed at autopsy being due to postmortem 

 imbibition from the blood and lymph. Quincke 3 found that 

 after subcutaneous injection of bilirubin only the connective 

 tissue, both cells and intercellular fibrils, becomes diffusely 

 colored ; later, it fades out of the cells, leaving only the fibrils 

 stained. Muscle-cells, fat-cells, and vessel-walls take up the 

 pigment only after their death. If the jaundice continues for 

 a long time, the subcutaneous deposits of bilirubin may undergo 

 a slow oxidation, the color changing to an olive or to a dirty 

 grayish green. The pigment in the connective tissues is at 

 first in solution, but may be deposited in a granular form after 

 a considerable amount has accumulated. 



The question whether in icterus the skin may be colored by 

 other pigments than bilirubin, especially by its reduction prod- 

 uct, hydrobilirubin or urobilin, seems to have been decided 

 negatively. This substance is formed from bilirubin by bac- 

 terial reduction in the intestines, is absorbed, and is probably 

 the source of the urobilin in the urine. No matter how much 

 hydrobilirubin is produced in the intestine, however, or how 



1 See Bickel, Exper. Untersuch. iiber der Pathol. der Cholaemie, Wiesbaden, 

 1900. 



2 See Ehrhardt, Arch. klin. Chir., 1901 (64), 314. 



3 Virchow's Arch., 1884 (95), 125. 



