Vasoconstrictor activity. These toxins cause cardiac arrest probably as a result of coronary vasospasm. Vasoconstrictor activity. Causes cardiac arrest probably as a result of coronary vasospasm (By similarity). Displays high agonistic activities towards endothelin-2 receptor (EDNRB) (displays affinity in the picomolar range) and endothelin-1 receptor (EDNRA) (lower affinities) (PubMed:21889567). Expressed by the venom gland. LD(50) is 0.015 mg/kg by intravenous injection into mice. LD(50) is 0.015 mg/kg by intravenous injection into mice. LD(50) is 0.015 mg/kg by intravenous injection into mice. LD(50) is 0.3 mg/kg by intravenous injection into mice. Belongs to the endothelin/sarafotoxin family.