408 PATHOLOGICAL PIGMENTATION 



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 adminis- 

 tration of atropin, which paralyzes the vagus, stops the brady- 

 cardia, indicating the importance of the effects of the bile salts 

 upon the vagus in causing this feature of cholemia. According 

 to Meltzer and Salant, 2 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. 



Since the bile salts cause hemolysis, and since in even 

 "hematogenous" jaundice they 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 obstruction to the outflow 

 of bile from the liver, and a "vicious circle " may 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 difficult always to eliminate 

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

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

 effect of the bile-pigments deposited in it. 



A remarkable tendency to spontaneous hemorrhages, frequently 

 observed in icterus, probably depends upon injury to the capil- 

 lary endothelium by the bile salts ; while the protracted, often 

 uncontrollable, hemorrhage that may occur from operation 

 wounds in icteric patients, is related to the slowed coagulation 

 of the blood observed in icterus. The cytotoxic effect of the 

 bile salts is also shown by the albuminuria of icteric persons, 

 which frequently results from the renal lesions the bile pro- 

 duces. 



Croftan 3 summarizes the physiological effects of bile acids as 

 follows : (1) A powerful cytolytic action, affecting both blood- 

 corpuscles and tissue-cells. (2) A distinct cholagogue action. 

 3) In small doses (1-500) they aid coagulation. (4) In large 

 oses (1250 and over) they retard coagulation. (5) Slow 

 the heart action. (6) In small doses they act as vasodilators ; 

 in large doses, as vasoconstrictors. (7) Reduce motor and 

 sensory irritability. (8) Act on the higher cerebral centers, 

 causing coma, stupor, and death. 



J See Minkowski, Ergeb. der Pathol., 1895 (2), 709. 



2 Jour. Exp. Med., 1906 (8), 128; review and literature concerning toxic- 

 ity of bile. 



3 New York Med. Jour., 1906 (83), 810 ; see also Faust, " Die tierische 

 Gifte," Braunschweig, 1906, p. 29. 



