ICTERUS 487 



Icllial (lose of bile will cause death, but the bile salts present in the 

 same (juantity of bile will not cause recognizable effects; unconibined 

 pigment is more toxic than its calcium or magnesium salts. Bile from 

 which the pigment is removed has very little toxicity. They suggest 

 that calcium is increased in the blood in icterus as a protection against 

 the toxic effects of the pigments. The combining of the calcium with 

 bile pigment, however, renders it unavailable for fibrin formation, and 

 this seems to be an important factor in the hemophilic tendency of 

 icterus.**^'' The decrease in available calcium may also be responsible 

 for the bradycardia and some of the mental and nervous symptoms. 



Bile salts are undoubtedly toxic, generally producing depression 

 of the central nervous system, with resulting coma and paralysis; 

 they are also decidedly toxic to cells of all sorts, causing hemolysis and 

 marked destiTiction of tissue-cells. Small quantities of bile salts 

 stimulate the central end of the vagus, and large amounts influence 

 the heart itself; hence in icterus we observe a slowing, and often an 

 irregularity, of the pulse, and the blood pressure is lowered. Al- 

 though there has been much dispute as to whether the chief effects of 

 icterus upon the heart depend upon action of the bile salts upon the 

 vagus, or upon the intracardiac ganglia, or upon the muscle itself,^" 

 yet Weintraud demonstrated that in some cases of icterus administra- 

 tion of atropin. which paralyzes the vagus, stops the bradycardia, 

 indicating the importance of the effects of the bile salts upon the 

 vagus in causing this feature of cholemia. According to ^leltzer and 

 Salant,"° bile also contains a tetanic element, which disappears from 

 stagnating bile ; the bile salts contain this tetanizing agent in less 

 amount than does the whole bile. But King ^^ and others ascribe most 

 of the effects of bile on the heart to the bile pigments, perhaps through 

 abstraction of the calcium. 



Since the bile salts cause hemolj^sis, and since in even "hematogen- 

 ous" jaundice they may enter the blood, it can readily be seen that in 

 this way an increased formation of bile-pigment may be incited which 

 leads to further obstiiiction to the outflow of bile from the liver, and 

 a "vicious circle" maj- thus be established. The necroses observed in 

 the liver in icterus, "icteric necrosis," are generally ascribed to the 

 cytotoxic effects of the bile salts, although it is difificult always to 

 exclude infection extending along the bile-ducts to the liver tissue. 

 Possibly the power of bile salts to dissolve lipoids may be responsible 

 for the cytotoxic effects "- as well as for the hemolysis. The itching 

 and irritation of the skin in icterus may be due to the effect of the 

 bile-salts deposited in it, for pruritis is said to be absent in the pig- 



88a See Lee and Vincent, Areli. Int. :Med., 10]5 (16), 59. 



89 See Minkowski. Erpeb. der Patiiol., lSf>5 (2), 709. 



90 Jour. Exp. Med., 1906 (8), 128; review and literature concerning toxicity of 

 bile. 



91 See King, Bigelow and Pearce, Jour. Exper. Med., 1912 (14), 159. 

 92Neufeld and Hiindel, Arb. kaiserl. Ges.-Amte, 1908 (28), 572. 



