Pro-inflammatory agent which mediates the degranulation of mast cells thus evoking an inflammatory response. In vivo, when injected into rats, diminishes the pain threshold. Induces dose-dependent paw edema in mice. Detected in the coelomic fluid. May be produced from vitellogenin or creatine kinase by limited proteolysis. Does not induce hemolysis in human erythrocytes and has no antibacterial properties.