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. 



Summary. 



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. 



