Susceptibility of erythrocytes of various animal species to the hemolytic and phospholipid splitting action of snake venom

A parallelism was found between hemolysis and erythrocyte phospholipid splitting induced by the action of cobra venom on washed erythrocytes of various species: guinea-pig, dog, human, rabbit. No significant phospholipid splitting was produced by cobra venom in camel and sheep erythrocytes, which are resistant to the hemolytic action of the venom. Isolated cobra venom phospholipase A (phosphatide acylhydrolase, EC 3.1.1.4) had no or slight hemolytic and phospholipid splitting action on the various erythrocytes, including those of the guinea-pig and dog, which are the most sensitive to the action of the whole venom. The different sensitivity of the various erythrocytes to the cobra venom is a reflection of their susceptibility to the action of venom direct lytic factor, a basic protein, which has hemolytic but no phospholipase activity. Isolated cobra venom phospholipase readily hydrolyzed the phospholipids of osmotic ghosts derived from both sensitive and resistant erythrocytes. Vipera palestinae venom which did not lyse the erythrocytes of any of the species tested, was also unable to hydrolyse the phospholipids in their osmotic ghosts. Cobra-venom direct lytic factor rendered the phospholipids of osmotic ghosts derived from sensitive erythrocytes available to the action of V. palestinae venom, but was not able to do so in the case of osmotic ghosts derived from resistant erythrocytes.