406 VENOM HEMOLYSIS 



According to this theory, therefore, any factor that modifies the 

 availability of the cell lecithin may modify the susceptibility of the cells 

 for hemolysis with cobra venom. 



Noguchi 1 has questioned the correctness of this view. He holds 

 that although lecithin exists in the stroma of all kinds of corpuscles, it is 

 not present in a form available for venom activation, and that the de- 

 gree of susceptibility to hemolysis depends chiefly upon the amount of 

 ether-soluble activators present in the cells, as, for example, fatty acids, 

 particularly oleinic acid, and their soluble soaps. In his opinion heating 

 an inactive serum to 65 C. and higher renders it active with venom, 

 owing to the presence of a protein compound of lecithin. 



A normal serum may, therefore, contain two activators, one being 

 thermolabile and resembling complement (inactivated by calcium chlo- 

 rid), and the other Joeing thermostabile and a protein lecithin. By add- 

 ing oleinic acid or its soluble soap to a non-activating serum the latter is 

 rendered highly active so far as venom hemolysis is concerned. Hence 

 while Kyes regards lecithin as the chief component of endocellular com- 

 plement, Noguchi regards the fatty acids, neutral fats, and soluble 

 soaps as the active agents. 



Other observers consider the fatty acids and soap as indirect activat- 

 ing agents in venom hemolysis, in that they possess the power of modi- 

 fying the cell and rendering the intracellular lecithin available for the 

 formation of complete hemolysin. 



On the other hand, in susceptible cells the union of cobra venom and 

 lecithin occurs directly with the formation of the complete hemolysin, 

 Kyes' cobra-lecithid,. due to the splitting of the fatty acid radical from 

 the lecithin. Ludecke, von Dungern, and Coca and Manwaring re- 

 gard this product as a venom-free lecithin derivative, and not as a leci- 

 thin. They prefer to call the active principle "cobralecithinase," and 

 the complete hemolysin" mono-fatty-acid-lecithin." 



According to Kyes, the relative amounts of lecithin and venom am- 

 boceptor show quantitative relationship comparable to serum ambo- 

 ceptors and complements, namely, that, within certain limits, the larger 

 the amount of venom, the smaller the amount of lecithin necessary to 

 effect hemolysis; and, conversely, the larger the amount of lecithin, the 

 smaller the amount of venom required. 



Further reference to the intimate relationship that exists between 

 lipoids and complements and hemolysis is also made in the discussion 

 on the nature of complements, on p. 351. 



1 Jour. Exp. Med., 1907, ix, 436. 



