3 1 2 IMMUNO-CATALYSIS 



and lysocephalin were hemolytic; lysolecithin showed an activity three 

 times as great as lysocephaHn. 



b. Physiological Consequences of the Action of Lysolecithin. The 

 studies of Feldberg and Kellaway (1937) on perfused lungs of guinea 

 pigs, cats, dogs and monkeys have shown that the injection of snake 

 venoms produces severe changes in the lungs and causes the appear- 

 ance of coagulable protein and of histamine in the outflowing fluids. 

 Increasing doses of venom caused increasing loss of histamine and the 

 amount of coagulable protein in the outflowing fluids also increased. 

 Those samples of perfusate containing the highest histamine concen- 

 tration were richest in protein. 



In the perfused lungs the venoms caused brancho-constriction 

 which was accounted for by the liberated histamine. The other changes 

 produced, however, could not be imitated by histamine. Crotalus atrox 

 caused the destruction of tissue. This effect, peculiar to this venom, 

 was considered to be due to proteolysis. Three venoms were studied, 

 all of which had one result in common— the swelling of the lung due 

 to accumulation of fluid and the appearance of glossy patches. As these 

 changes were paralleled by the loss of histamine from the lung, it 

 looked as though they might be caused by histamine. 



Following the above study with snake venom Feldberg and Kellaway 

 (1938) conceived the idea that the formation of hemolytic lysolecithin 

 by the venom lecithinase might account for effects of the venom other 

 than hemolysis, and that its formation in the tissues might make the 

 cells permeable to their histamine. Consequently they found that the 

 active substance or substances responsible for the above symptom- 

 atology could be extracted with methyl alcohol from the venomed 

 liver of the monkey; and the actions of such extracts were compared 

 with that of "lysolecithin" obtained from an alcoholic extract of lecithin 

 treated with cobra venom. Both extracts had similar effects on widely 

 different tissues, but there were some quantitative differences. At least 

 part of the hemolytic activity of both extracts was attributable to 

 lysolecithin; and the quantitative agreement between the extracts in 

 hemolytic power, in ability to liberate histamine, and in toxicity for 

 the guinea pig suggested that all these actions result from the presence 

 of lysolecithin. Since the active substances in both extracts appeared 

 to be formed by the action of venom on lipids, provisionally their total 

 activity was regarded as being due to lysolecithin-like substances. The 



