XXXV. A STUDY OF THE SUBSTANCES WHICH 

 ACTIVATE COBRA VENOM. 1 



BY 



Dr. PRESTON KYES, Dr HANS SACHS, 



Associate in Anatomy. University of Assistant at the Royal Institute 

 Chicago, Fellow of the Rockefeller for Experimental Therapy, 



Institute for Medical Research. Frankfurt-on-Main. 



I. Concerning the' Activation of Cobra Venom by Means of 



Complements. 



IN a previous study 2 one of us has shown that cobra venom is 

 activated not only by certain active sera but also by lecithin and 

 certain complement-like substances of the red blood-cells called 

 "endocomplements." This, of course, harmonizes with the ambo- 

 ceptor nature of the poison which had been demonstrated by Flexner 

 and Noguchi. 3 In view of the wide distribution of lecithin in the 

 organs and tissues it seemed advisable to penetrate deeper into the 

 mechanism of cobra-venom haemolysis, especially in order to deter- 

 mine if the assumption of complements and endocomplements is 

 not superfluous and the presence of lecithin in the red blood-cells 

 and serum sufficient to explain the complement action. It is true 

 that certain sera which activate cobra venom lose this property when 

 they are heated to 56 C. for half an hour, and the endocomplements 

 produced by dissolving the red blood-cells in water are inactivated 

 by heating to 62 C. Considering the great ease with which lecithin 

 combines with albuminous bodies, etc., it was possible that the 

 thermolability of the activating factors was simulated by a com- 

 bination of the lecithin with other substances. An important fact 

 which speaks strongly against this view, however, is one first brought 



1 Reprint from the Berlin klin. Wochensch. 1903, Nos. 2 and 4. 



2 P. Kyes. See page 291. 



3 Flexner and Noguchi, Snake Venom in Relation to Haemolysis, Bacteri- 

 olysis, and Toxicity, Journ of Exp. Medicine, Vol. VI, No. 3, 1902. 



443 



