Description: Sarafotoxin S6d (STX-b) is a peptide toxin isolated from the venom of the Israeli burrowing asp. It induces various Electrocardiogram (ECG) changes such as myocardial ischemia and hyperkalemia. In rat aortas, Sarafotoxin S6d causes intense vasoconstriction dependent on extracellular calcium ions and exhibits positive inotropic effects in rat atria. This compound is useful for research into cardiovascular diseases.