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.

Sarafotoxin S6d, administered intravenously at dosages of 0.3, 1.0, and 3.0 nmol/kg, consistently produces a sustained pressor effect and a transient increase in pulse pressure. However, at a higher dosage of 5.0 nmol/kg, Sarafotoxin S6d initially raises the blood pressure, heart rate, and respiratory rate, only to precipitate a rapid decline in these parameters, leading to death within 10 minutes in most mice. At this dosage, there is also a significant elevation in K+ levels by 159%. Furthermore, plasma enzymes such as LDH, CPK, IP, and glucose levels show notable increases, with LDH rising by 60%, CPK by 91%, IP by 137%, and glucose by 80%.