CHAPTER XI 



HEMOGLOBIN CATABOLISM, I. BREAKDOWN 

 TO BILE PIGMENTS 



1. INTRODUCTION 



1.1. Formation of Bile Pigments from Hemoglobin 



The conception that bile pigment is derived from hemoglobin is 

 probably very old (Virchow ascribes it to Breschet, 2889), but the 

 first clear indication came from the observations of Virchow (2889) 

 in 1847. He produced evidence showing that "hematoidin," the 

 orange pigment found at the site of old blood extravasations was 

 similar to bilirubin. Although a long controversy (cf. 22^0) took place 

 as to whether hematoidin was identical with bilirubin, Fischer and 

 Reindel (868) in 1923 identified the hematoidin from a liver cyst as 

 bilirubin. The last doubt was removed, when Rich and Bumstead 

 (224-2) obtained the same result with hematoidin from a hemor- 

 rhagic cyst of the omentum; in this case the bile was excluded as the 

 source of bilirubin. 



The transformation of hemoglobin into bilirubin in animal experi- 

 ments was probably first observed by Frerichs and Stadeler (952) in 

 1850, when they observed bilirubin excretion in the urine after injec- 

 tion of bile acids. For a short time (cf. 221^0) it was thought that the 

 bile acids were necessary for the formation of bilirubin, although 

 Kuhne (1595) had drawn attention to the fact that bile acids cause 

 hemolysis. When Herrmann (1246) in 1859 obtained bilirubinuria 

 after injection of distilled water, the bile acids were eliminated as 

 possible precursors. It was not until Tarchanoff (2739), working 



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