542 XI. HEMOGLOBIN CATABOLISM, I 



tributes greatly to hemoglobin breakdown as the beneficial effect of splenec- 

 tomy in some forms of hemolytic anemia shows {cf. Section 6.2.). It is not 

 yet clear, however, whether a normal spleen acts on abnormal red cells, as 

 supported by some workers {522,2566), or whether an abnormal mechanism 

 is active in the spleen, at least in acquired hemolytic anemia (Heilmeyer, 

 1210,1212,121Ji).* The role of the spleen in toluylene diamine jaundice may 

 be rather indirect (1294,1392). 



The importance of the spleen for hemolytic processes has been referred 

 to in Sections 5.8. and 6.2. Granick {1031) found a high nonhematin iron 

 content in erythrocytes from the teased spleens of various animals {cf., 

 however, the criticism of the technique by Case, 416). It is particularly 

 interesting to note that splenectomy causes an increase of the siderocyte 

 count in humans {611); this indicates that the spleen removes the damaged 

 cells. 



As far back as 1926 Mann and co-workers {1859) observed the appearance 

 of an absorption band at 630 m/n in oxyhemoglobin solutions after their 

 perfusion through the dog spleen. This band was ascribed to "acid hematin," 

 not hemoglobin. Among other possibilities, it may have been due to chole- 

 globin, although Lemberg and Legge {1703) in similar experiments with rabbit 

 spleen found a scarcely significant choleglobin formation. 



Bone marrow. Mann and co-workers {311,1859) and London and Kry- 

 zanowskaja {1777) have shown that bile pigment is also formed in the bone 

 marrow. Even after excision of abdominal organs, bilirubin appeared in the 

 plasma, and the bilirubin content of the femoral vein was higher than that 

 of the femoral artery, though the difi^erence was not as marked as in the 

 spleen. 



The increased bile pigment formation in pernicious anemia perhaps 

 occurs largely in the bone marrow. 



7.4. Observations on Formation and Occurrence of 

 Choleglobin and Sulfhemoglobin in Tissues Other Than Blood 



One to two hours after intravenous injection of hemoglobin into the dog, 

 Kiese {1525) analyzed the blood, the spleen, and the liver for "verdoglobin." 

 The amount of verdoglobin found in these tissues accounted for 5, 12, and 

 20% of the injected blood pigment, respectively. It is open to doubt whether 

 the choleglobin formation occurring readily in tissue extracts in vitro has 

 been obviated in these experiments. Kiese considered the pigment to be 

 verdoglobin S {i.e., sulfhemoglobin) on account of the position of the absorp- 

 tion band of the carboxy compound. 



Since it has been shown that a variety of reducing substances and systems 

 present in organs are able to form choleglobin from oxyhemoglobin, the 

 mere demonstration of choleglobin formation by tissue breis or extracts 

 adds little to our knowledge. The same holds for the formation of sulfhemo- 

 globin in the liver, the liver being known to contain enzymes which produce 

 hydrogen sulfide from cysteine. Such experiments have been carried out 

 by Kiese {1522) and by Polonovski and co-workers {210). Kiese's observa- 



* Cf. footnote on p. 537. 



