Comparison of the in vitro neuromuscular activity of venom from three Australian snakes (Hoplocephalus stephensi, Austrelaps superbus and Notechis scutatus): efficacy of tiger snake antivenom.
1. Tiger snake antivenom, raised against Notechis scutatus venom, is indicated not only for the treatment of envenomation by this snake, but also that of the copperhead (Austrelaps superbus) and Stephen's banded snake (Hoplocephalus stephensi). The present study compared the neuromuscular pharmacology of venom from these snakes and the in vitro efficacy of tiger snake antivenom. 2. In chick biventer cervicis muscle and mouse phrenic nerve diaphragm preparations, all venoms (3-10 microg/mL) produced inhibition of indirect twitches. In the biventer muscle, venoms (10 micro g/mL) inhibited responses to acetylcholine (1 mmol/L) and carbachol (20 micromol/L), but not KCl (40 mmol/L). The prior (10 min) administration of 1 unit/mL antivenom markedly attenuated the neurotoxic effects of A. superbus and N. scutatus venoms (10 microg/mL), but was less effective against H. stephensi venom (10 microg/mL); 5 units/mL antivenom attenuated the neurotoxic activity of all venoms. 3. Administration of 5 units/mL antivenom at t90 partially reversed, over a period of 3 h, the inhibition of twitches produced by N. scutatus (10 microg/mL; 41% recovery), A. superbus (10 microg/mL; 25% recovery) and H. stephensi (10 microg/mL; 50% recovery) venoms. All venoms (10-100 microg/mL) also displayed signs of in vitro myotoxicity. 4. The results of the present study indicate that all three venoms contain neurotoxic activity that is effectively attenuated by tiger snake antivenom.
Hodgson
Wayne C
WC
Monash Venom Group, Department of Pharmacology, Monash University, Clayton, Australian Venom Research Unit, Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia. wayne.hodgson@med.monash.edu.au
Eriksson
Christer O
CO
Alewood
Paul F
PF
Fry
Bryan G
BG
D017836:Agkistrodon; D000818:Animals; D001315:Australia; D002645:Chickens; D003435:Crotalid Venoms / Q000037:antagonists & inhibitors / Q000494:pharmacology; D003964:Diaphragm / Q000187:drug effects / Q000502:physiology; D004546:Elapid Venoms / Q000037:antagonists & inhibitors / Q000494:pharmacology; D017815:Elapidae; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009465:Neuromuscular Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology; D009469:Neuromuscular Junction / Q000187:drug effects* / Q000502:physiology; D010791:Phrenic Nerve / Q000187:drug effects / Q000502:physiology; D012910:Snake Venoms / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D012911:Snakes; D013045:Species Specificity
D003435:Crotalid Venoms; D004546:Elapid Venoms; D009465:Neuromuscular Agents; D012910:Snake Venoms; C072139:Notechis 11'2