402 Fatty Acids in Human Blood 
2 
From the point of view of hemolytic action, we are especially | 
interested in the unsaturated part of the fatty acids, since it has 
been shown by Noguchi‘ and Faust and Tallquist® that the higher 
saturated acids, palmitic and stearic, are not hemolytic either 
as such or as their soaps. On the other hand, the unsaturated 
fatty acids, as oleic acid, have a strong hemolytic action, and it 
has been demonstrated by Faust and Tallquist that this acid is 
_the cause of the anemia in Bothriocephalus latus infection.’ Fur- 
ther, Lamar’ has shown an existing relation between the degree 
of unsaturation and lytic action as he was able to show that the 
sodium soap of linoleic acid dissolved pneumococci more rapidly 
in higher dilutions than sodium oleate. McPhedran,® working 
with red blood cells, was unable to demonstrate any difference 
in the lytic action of linoleic and oleic acids as Lamar had claimed 
in the case of bacteria, and concluded that there was no relation- 
ship between the lytic action and degree of unsaturation. 
In my previous paper,’ I reported that the iodine number of 
fatty acids of the blood in cases of pernicious anemia was not 
exceptionally high; but, as I stated, the matter needed further 
investigation, as the material used for iodine determinations was 
a mixture of saturated and unsaturated fatty acids; so that this 
finding had no other meaning than that unsaturated fatty acids 
were present. The mere presence of unsaturated fatty acids 
cannot be considered the primary cause of toxic hemolysis, since 
such acids exist in normal human blood, as shown below. It is 
therefore necessary to look further for the causative factor. 
4 Noguchi, H., J. Exp. Med., 1906, viii, 87. 
5 Faust, E. 8., and Tallquist, T. W., Arch. exp. Path. u. Pharm., 1907, 
ivi; "367; 
6 The cholesterol ester of oleic acid is hemolytic but not so strongly so 
as Oleic acid itself. Since they demonstrated in the saponified ether ex- 
tract of Bothriocephalus latus both oleic acid and cholesterol and were 
unable to show the presence of glycerol, they concluded that the oleic 
acid was present as a cholesterol ester without attempting to isolate it as 
such. 
7 Lamar, R. V., J. Exp. Med., 1911, xiv, 256. 
8 McPhedran, W. F., J. Exp. Med., 1913, xviii, 527. 
9 Csonka, F. A., J. Biol. Chem., 1916, xxiv, 431. 
