LIPID STORAGE UNDER ABNORMAL CONDITIONS 705 



If the cerebrosides in the spleen and other organs do not accumulate from 

 the blood, another source of starting material must necessarily be available. 

 Thannhauser 917 and Thannhauser and Schmidt 922 suggested that lignoceryl- 

 sphingosine or other ceramides might be the starting materials. A com- 

 pound of this nature could be converted to the glucose or galactose type of 

 cerebroside by condensation with the appropriate sugar, or to sphingo- 

 myelin by condensation with choline phosphate. This suggestion is sup- 

 ported by the fact that lignocerylsphingosine has been found to be present 

 in these organs, together with cerebrosides and sphingomyelin. 970 More- 

 over, a glucoside-splitting enzyme has been detected in the spleen 971 ; 

 if its action is reversible, as is believed to be the case with most enzymes, it 

 would be able to catalyze the synthesis of cerebroside by the combination of 

 lignocerylsphingosine and glucose or galactose. Figure 5 affords a graphic 

 explanation of this hypothesis. 



(4) Atheroma in Arteriosclerosis 



The formation of atheroma in the walls of the blood vessels has long been 

 recognized to be a concomitant of arteriosclerosis. A number of different 

 investigators 972-976 proved that the atheromatous vessels contain excessive 

 amounts of lipids, especially cholesterol; these lipid deposits accumulate in 

 the atheromatous patches. 



The question as to the cause of the deposition of cholesterol and of other 

 lipids in the walls of the blood vessels is still unsolved. Apparently, al- 

 though hypercholesterolemia is a condition which sometimes accompanies 

 hypertension, it is not a constant symptom. When hypercholesterolemia 

 can be demonstrated, the increase in this component is slight and variable. 

 In certain cases of xanthomatosis, much larger deposits of lipids may occur 

 without the occurrence of a hyperlipemia. In the late stages of arterio- 

 sclerosis, calcium deposits replace the lipids in the atheroma, without the 

 development of hypercalcemia. Although Burger, 977 Rosenthal, 974 and 

 Faber 978 have demonstrated increasing cholesterol concentrations in the 



970 E. Frankel, F. Bielschowsky, and S. J. Thannhauser, Z. physiol. Chem., 218, 1-11 

 (1933). 



971 S. J. Thannhauser and M. Reichel, /. Biol Chem., US, 311-317 (1936). 



972 T. Leary, Arch. Pathol, 32, 507-555 (1941). 



973 C. S. McArthur, Biochem. J., 36, 559-570 (1942). 



974 S. R. Rosenthal, Arch. Pathol, 18, 473-506, 660-698, 827-842 (1934). 

 976 R. Schonheimer, Z. physiol Chem., 160, 61-76 (1926). 



976 R. Schonheimer, Z. -physiol. Chem., 177, 143-157 (1928). 



977 M. Burger, Ergeb. inn. Med. Kinderheilk., 34, 683-701 (1928). 



978 M. Faber, Arch. Pathol, 48, 342-350 (1949). 



