A novel cardiotoxic polypeptide from the venom of Atractaspis engaddensis (burrowing asp): Cardiac effects in mice and isolated rat and human heart preparations

Three apparent receptor subtypes for the endothelin/sarafotoxin family

“…We recently characterized a high-affinity receptor for the cardiotoxic vasoconstrictor peptides, the sarafotoxins (SRTX), and for the vasoconstrictor peptides, endothelins (ET), in the rat heart and brain, and demonstrated the association of this receptor with phosphoinositide hydrolysis [1][2][3][4][5]. The sarafotoxins (SRTX-a, SRTX-b and SRTX-c [6,7]) and their structurally related mammalian vasoconstrictor peptides the endothelins (ET-1, ET-2, ET-3) [8,9] (see fig.l) were found to share many similarities in binding to their receptor, in their ability to induce phosphoinositide hydrolysis, regional distribution ( [10] and references therein) and vasoconstrictive activities [8,9,11].…”

Cerebral Blood Flow, Metabolism, and Head Trauma

“…In addition to the unique fang anatomy, the grossly elongated venom glands produce very uncharacteristic venom. Analyses of the snake venom led to the discovery of a new class of toxins with powerful vasoconstrictory cardiovascular effects and extreme toxicity (Kochva et al 1982 ;Wollberg et al 1988 ) . The analysis of the venom revealed several isotoxins (21 amino acid-long polypeptides) that were subsequently isolated and sequenced.…”

“…It is the cardiotoxic effects of these isopeptides which fi rst began to attract the focus of researchers to the ET system in the late 1980s. In experiments by Wollberg et al 1988 , animals given SRTX-b exerted three separate effects: A-V conduction block, positive inotropicity, and vasoconstriction. Later, Vierhapper et al 1990 demonstrated in human volunteers that infusion of ET-1, which is similar in structure and function to SRTX-b, resulted in a marked rise in blood pressure.…”

Structure‐activity relationship in vasoconstrictor effects of sarafotoxins andendothelin‐1

“…It has been reported that SRTb provides powerful coronary vasoconstriction, positive inotropic effect and severe atrioventricular block in mice, rats and humans [3]. Sarafotoxins consist of 21 amino acid residues with two sets of intrachain disulfide linkages [4] and show a high sequence homology with endothelin-1 (ET-l) [5], a potent vasoconstrictor peptide obtained from porcine aortic endothelial cells [6].…”