Respiratory Effects of Sarafotoxins from the Venom of Different Atractaspis Genus Snake Species

Abstract

Sarafotoxins (SRTX) are endothelin-like peptides extracted from the venom of snakes belonging to the Atractaspididae family. A recent in vivo study on anesthetized and ventilated animals showed that sarafotoxin-b (SRTX-b), extracted from the venom of Atractaspis engaddensis, decreases cardiac output by inducing left ventricular dysfunction while sarafotoxin-m (SRTX-m), extracted from the venom of Atractaspis microlepidota microlepidota, induces right ventricular dysfunction with increased airway pressure. The aim of the present experimental study was to compare the respiratory effects of SRTX-m and SRTX-b. Male Wistar rats were anesthetized, tracheotomized and mechanically ventilated. They received either a 1 LD50 IV bolus of SRTX-b (n = 5) or 1 LD50 of SRTX-m (n = 5). The low-frequency forced oscillation technique was used to measure respiratory impedance. Airway resistance (Raw), parenchymal damping (G) and elastance (H) were determined from impedance data, before and 5 min after SRTX injection. SRTX-m and SRTX-b injections induced acute hypoxia and metabolic acidosis with an increased anion gap. Both toxins markedly increased Raw, G and H, but with a much greater effect of SRTX-b on H, which may have been due to pulmonary edema in addition to bronchoconstriction. Therefore, despite their structural analogy, these two toxins exert different effects on respiratory function. These results emphasize the role of the C-terminal extension in the in vivo effect of these toxins.

Snake Venom Peptides: Tools of Biodiscovery

“…This difference of action of both peptides was also attributed to a C-terminus extension for the long isoforms. C-terminal extension can result in different spatial conformation of the two peptides [ 163 ]. SRTXs can serve to better understand the endothelin system and related diseases, such as pulmonary hypertension, asthma, and/or heart failure [ 163 , 164 , 165 ].…”

Factor X activating Atractaspis snake venoms and the relative coagulotoxicity neutralising efficacy of African antivenoms

“…Despite their evolutionary novelty and documented severe envenomation effects, their venom is underinvestigated relative to the intensive efforts on elapid and viperid snake venoms. Work to-date has largely focused on the endothelin-type peptides called sarafotoxins which are responsible for the dramatic rise in blood pressure observed clinically (Abd-Elsalam, 2011;Atkins et al, 1995;Borgheresi et al, 2001;Goyffon, 1994;Ismail et al, 2007;Kawanabe and Nauli, 2011;Kolb, 1991;Mahjoub et al, 2015;Malaquin et al, 2016;Nakajima et al, 1989;Nayler et al, 1989;Patocka et al, 2004;Takasaki et al, 1992;Tilbury and Verster, 2016;Warrell et al, 1976). The only other characterized toxin type from Atractaspis venom has been a hemorrhagic metalloprotease (Ovadia, 1987).…”

Necrosis and amputation following the bite of the Bibron’s stiletto snake (Atractaspis bibronii) with a concise review of current literature

“…Sarafotoxins are particular to Atractaspis species and demonstrate high-affinity for mammalian endothelin-receptors in vivo. 18,[21][22][23] with potential for potent vasoconstriction of smooth muscle. Serious injury with Atractaspis , is nonetheless, rare.…”