528 XI. HEMOGLOBIN CATABOLISM, I 



cytosis, is brought about when only a part of the pigment is destroyed. 

 This is in agreement with the direct analyses made of intracorpuscular 

 biliverdin after phenylhydrazine (170^). The remainder of the hemo- 

 globin is destroyed outside the red cell {cf. Sections 7 and 8). 



While choleglobin is found in arsine poisoning, it is still doubtful 

 whether the extreme rapidity of the hemolysis by this substance is 

 due to the rapidity of choleglobin formation, or whether oxidation 

 products of arsine, formed by the coupled oxidation, have a specific 

 hemolyzing action (cf. Chapter X, Section 4.4.4.). 



5.5. Changes in Stored Blood 



Although red cells stored in the presence of an anticoagulent cannot 

 be considered as being under truly physiological conditions, they are 

 undoubtedly nearer such conditions than when in the presence of 

 phenylhydrazine in vitro or in vivo. However, most of the chemical 

 and histological changes discussed in the previous sections have been 

 observed in stored blood. 



Case (416) has carried out siderocyte counts in blood stored under a 

 number of conditions. In human blood in 3.8% citrate, stored at 20°C., 

 without shaking, the siderocyte count increased from 0.5 to 5% in 24 hours, 

 the count remaining above the original level for about 17 days. Similar 

 observations were made with cats' and dogs' blood. Shaking the blood pro- 

 duced irregular cyclic changes. The highest siderocyte count recorded in the 

 series (25%) was obtained in an experiment in which blood was stored under 

 paraffin. It is tempting to assume that this may be due to the greater rate 

 of coupled oxidation of hfmoglobin with hydrogen donors under lowered 

 oxygen tension {cf. Chapter X, Section 4.4.1.), particularly since carbon 

 monoxide inhibited the formation of siderocytes. Control experiments 

 showed that siderocytes appeared at approximately the same rate in hepar- 

 inized or oxalated blood as in citrated blood, as well as in clots in the presence 

 and absence of leucocytes. 



In view of the influence of glucose on prolonging the life of stored blood, 

 Case attaches considerable importance to experiments in which blood stored 

 in glucose citrate at 4°C. showed the first siderocyte peak at 15 days, as 

 against 5 days in blood stored in citrate without glucose. 



That the extrusion of the iron granules took place under th^e 

 conditions is shown by the increase in the plasma iron, which took 

 place steadily during the experiment. Such an increase had been 

 observed previously by Barkan and Walker (166). 



Moeschlin (1967) was apparently the first to observe the appear- 

 ance of Heinz bodies in human blood maintained in citrate, and to 



