CHAPTER XII 



HEMOGLOBIN CATABOLISM, II. HEMATIN 

 AND PORPHYRINS 



1. INTRODUCTION 



In this chapter we deal with substances which arise during patho- 

 logic catabolism of hemoglobin but which are not formed in normal 

 hemoglobin breakdown. Hematin and porphyrins have in the past 

 been, and by some workers are still, held to be products of hemo- 

 globin catabolism or intermediates in bile pigment formation, but 

 we shall show that the evidence in favor of such an assumption is 

 unconvincing. Other substances which occur pathologically, such as 

 increased amounts of hemiglobin, and also sulfhemoglobin, have been 

 discussed in the preceding chapter (Chapter XI, 5.). 



2. METABOLISM OF HEMATIN 

 2.1. Hematin and Methemalbumin in Blood Plasma 



"Hematin" was first found in human plasma by Schumm in 

 1912 {2Jf88,2Jt90,2500) by the sensitive hemochrome test (c/. Chap- 

 ter VI, Section 3.3.5.). It has subsequently been found by several 

 workers in a variety of pathologic conditions. 



These include hemolytic anemia {232,239,7Jt2,1201,2m,2m,2500,2507), 

 nocturnal hemoglobinuria (733,735), icterus neonatorum (267,269,1150, 

 1233), pernicious anemia, particularly before treatment (265,267,638,735, 

 7U2;1213, p. 191 ; 2 Jt88, 21^90, 2500, 2507), and occasionally also after the begin- 

 ning of remission (2989), malarial hemolytic anemia (638,735,736,2488,2^90, 

 2500,2507), septicemia (269, 638, 7 35, 2 A52, 2 Jt88, 2 490, 2500, 2507), acute yellow 



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