554 THE RELATION OF COLLOIDS AND LIPOIDS TO IMMUNITY 



Relation of Lipoids to Hemolysis. (a) From the standpoint of 

 immunity, venom hemolysis is of peculiar interest as indicating the pos- 

 sible important relation of lipoids to hemolytic complement. Granting 

 that venom contains a hemolytic amboceptor (Flexner and Noguchi), 

 the complementing substance must be derived from the corpuscles, and, 

 according to Kyes, this complementary agent is represented in lecithin. 

 Kyes was able to produce what he considers are compounds of the hemo- 

 lysin with lecithin, namely, "lecithids." Whether these "lecithids" 

 are true compounds of hemolysins and corpuscular lecithin or simply the 

 active hemolytic products of the cleavage of lecithin by ferments con- 

 tained in the venom, is at present unknown. Noguchi and Lieberman 

 have shown that not only lecithin, but soap as well, especially unsatu- 

 rated fatty acids, and probably protein compounds of soaps and lecithin, 

 may act as the hemolytic complement and activate the hemolysin of the 

 venom. Lipoids from bacteria and trypanosomes have been found to 

 possess similar properties. Hemolytic lipoids have been secured from 

 serum, and the complementary activity of a fresh normal serum may be 

 destroyed by fat solvents, e. g., ether. While other investigators have 

 not been able to confirm Noguchi's attempts to produce an artificial 

 complement of fatty substances of exactly the same properties as serum 

 complement, this work indicates most strongly the close relation of 

 serum complement to lipoids. 



(b) The hemotoxic activity of various toxins is probably dependent 

 largely upon their action on the lipoids of red corpuscles. The saponin 

 substances, l a group closely related to glucosids, and found in at least 

 46 different families of plants, are strongly hemolytic. Ransom 2 has 

 found that an ethereal extract of red corpuscles contains a substance 

 that inhibits saponin hemolysis. This substance consists largely of 

 cholesterin, and it is the presence of cholesterin in normal serum that 

 inhibits saponin hemolysis. This may be demonstrated experimentally 

 by adding cholesterin to a solution of a saponin. Noguchi 3 has shown 

 that lecithin does not possess the same antihemolytic action on saponin. 

 It would appear, therefore, that saponin causes hemolysis by combining 

 with, altering, or dissolving the lipoids of the stroma of corpuscles. The 

 resistance of corpuscles to saponin hemolysis varies in certain diseases, 

 being especially low in jaundice (McNeil) 4 . 



1 Complete literature on saponin, see Robert "Die Saponinsubstanzen," Stutt- 

 gart, 1904. 



2 Deut. med. Wochenschr., 1901, 27, 194. 



3 Univ. of Penna. Med. Bull., 1902, 15, 327. 



4 Jour. Path, and Bact., 1910, 15, 56. 



