Vasoconstrictor activity. These toxins cause cardiac arrest probably as a result of coronary vasospasm. May act by displaying agonistic activities towards endothelin-1 and -2 receptors (EDNRA and EDNRB). Expressed by the venom gland. LD(50) is 0.35 mg/kg by intravenous injection. Belongs to the endothelin/sarafotoxin family.