Species Dependent Variations in the in Vitro Myotoxicity of Death Adder (Acanthophis) Venoms

• Published in: Toxicological Sciences
• Main Authors: Wickramaratna, Janith C., Fry, Bryan G., Hodgson, Wayne C.
• Format: Text
• Language: English
• Published: Oxford University Press 2003
• Subjects: In Vitro Toxicology and Alternative Testing; Antarc*; antarcticus
• Online Access: http://toxsci.oxfordjournals.org/cgi/content/short/kfg144v1; https://doi.org/10.1093/toxsci/kfg144

Based on early studies on Acanthophis antarcticus (common death adder) venom it has long been thought that death adder snake venoms are devoid of myotoxicity. However, a recent clinical study reported rhabdomyolysis in patients following death adder envenomations, in Papua New Guinea, by a species thought to be different to A. antarcticus . Subsequently, a myotoxic phospholipase A 2 component was isolated from A. rugosus (Irian Jayan death adder) venom. The present study examined the venoms of A. praelongus (northern), A. pyrrhus (desert), A. hawkei (Barkly Tableland), A. wellsi (black head), A. rugosus , A. sp. Seram and the regional variants of A. antarcticus for in vitro myotoxicity. Venoms (10-50 µg/ml) were examined for myotoxicity using the chick directly (0.1 Hz, 2 ms, supramaximal V) stimulated biventer cervicis nerve-muscle preparation. A significant contracture of skeletal muscle and/or inhibition of direct twitches were considered signs of myotoxicity. This was confirmed by histological examination. All venoms displayed high phospholipase A 2 activity. The venoms (10-50 µg/ml) of A. sp. Seram, A. praelongus , A. rugosus and A. wellsi caused a significant inhibition of direct twitches and an increase in baseline tension compared to the vehicle ( n = 4-6; two-way ANOVA, p < 0.05). Furthermore, these venoms caused dose-dependent morphological changes in skeletal muscle. In contrast, the venoms (10-50 µg/ml; n = 3-6) of A. hawkei , A. pyrrhus and regional variants of A. antarcticus were devoid of myotoxicity. Prior incubation (10 min) of CSL death adder antivenom (5 units/ml) prevented the myotoxicity caused by A. sp. Seram, A. praelongus , A. rugosus and A. wellsi venoms (50 µg/ml; n = 4-7). In conclusion, clinicians may need to be mindful of possible myotoxicity following envenomations by A. praelongus , A. rugosus , A. sp. Seram and A. wellsi species.