HEMOLYTIC PROPERTIES OF HELODERMA VENOM. 



161 



When dog serum heated to 56° C. was used as an activator, the inhibitory 

 action was not so marked as when lecithin or horse serum was used as an acti- 

 vator, and we could only partially prevent hemolysis of guinea-pig corpuscles. 

 In these experiments only heated guinea-pig serum was used. 



With sodium oleate as an activator, the guinea-pig serum also inhibited 

 the hemolytic action. In this case the inhibiting action of guinea-pig serum 

 was not so strong as with lecithin, more pronounced than with dog serum and 

 about equally strong with horse serum as an activator. 



Stoimahy. 



Guinea-pig serum inhibits the hemolysis by lecithin and venom of guinea- 

 pig and horse corpuscles, and only a little less markedly that of turtle and 

 heloderma corpuscles. Hemolysis of horse corpuscles by venom and heated 

 horse serum is also markedly inhibited, while hemolysis of guinea-pig corpus- 

 cles by similar mixtures is slightly less markedly inhibited. The action of 

 venom and sodium oleate on guinea-pig corpuscles is considerably interfered 

 with by guinea-pig serum but the action of heated dog serum and venom is only 

 slightly affected. On the other hand, guinea-pig serum does not inhibit the 

 hemolysis of dog corpuscles by venom and lecithin, nor can any influence of 

 guinea-pig serum be observed when rabbit corpuscles were mixed with venom 

 plus lecithin or horse serum. Unheated guinea-pig serum acts in the same 

 manner as heated guinea-pig serum. 



Heloderma serum, like guinea-pig serum, has marked inhibitory power, 

 the unheated and heated serum acting in a similar manner, but the inhibitory 

 power of the heated serum is, perhaps, slightly stronger than that of the un- 

 heated serum, as shown in the following : 



Mixture of 0.2 mg. of venom plus 

 0.1 mg. of lecithin and 1 c.c. of 

 a 5 per cent suspension of helo- 

 derma corpuscles. 



Mixture of 0.'2 mg. of venom and 

 • 0.1 mg. of lecithin. 



It will be noted that heloderma serum exhibits a greater inhibitory power 

 than guinea-pig serum, since 0.05 c.c. of the former is able entirely to prevent 

 hemolysis, while 0.1 c.c. of guinea-pig serum allows a trace of hemolysis to take 

 place, although more venom had been added in the experiment with heloderma 

 venom. 



The action of a mixture of venom and lecithin on turtle and guinea-pig 

 corpuscles was also inhibited by the heated heloderma serum. 



