Tags

Type your tag names separated by a space and hit enter

Solving the 'Brown snake paradox': in vitro characterisation of Australasian snake presynaptic neurotoxin activity.
Toxicol Lett. 2012 May 05; 210(3):318-23.TL

Abstract

Pseudonaja textilis (Eastern Brown snake) and Oxyuranus scutellatus scutellatus (Coastal taipan) are clinically important Australian elapid snakes, whose potent venoms contain the presynaptic (β) neurotoxins, textilotoxin and taipoxin, respectively, and a number of postsynaptic neurotoxins. However, while taipan envenoming frequently results in neurotoxicity, Brown snake envenoming causes an isolated coagulopathy and neurotoxicity is rare. This phenomenon is called the 'Brown snake paradox'. This study compared the pharmacology of both venoms and their respective presynaptic neurotoxins to investigate this phenomenon. From size-exclusion high performance liquid chromatography (HPLC) analysis textilotoxin represents a significantly smaller proportion (5.7%) of P. textilis venom compared to taipoxin in O. s. scutellatus venom (20.4%). In the chick biventer cervicis nerve-muscle (CBCNM) preparation both venoms caused concentration-dependent neurotoxicity, with P. textilis venom being significantly more potent than O. s. scutellatus venom. Conversely, taipoxin was significantly more potent than textilotoxin when compared at the same concentration. Textilotoxin only partially contributed to the overall neurotoxicity of P. textilis venom, while taipoxin accounted for the majority of the neurotoxicity of O. s. scutellatus venom in the CBCNM preparation. Compared with taipoxin, textilotoxin is less potent and constitutes a smaller proportion of the venom. This is likely to be the reason for the absence of neurotoxicity in envenomed humans thus explaining the 'Brown snake paradox'.

Authors+Show Affiliations

Monash Venom Group, Department of Pharmacology, Monash University, Victoria, Australia.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22343038

Citation

Barber, Carmel M., et al. "Solving the 'Brown Snake Paradox': in Vitro Characterisation of Australasian Snake Presynaptic Neurotoxin Activity." Toxicology Letters, vol. 210, no. 3, 2012, pp. 318-23.
Barber CM, Isbister GK, Hodgson WC. Solving the 'Brown snake paradox': in vitro characterisation of Australasian snake presynaptic neurotoxin activity. Toxicol Lett. 2012;210(3):318-23.
Barber, C. M., Isbister, G. K., & Hodgson, W. C. (2012). Solving the 'Brown snake paradox': in vitro characterisation of Australasian snake presynaptic neurotoxin activity. Toxicology Letters, 210(3), 318-23. https://doi.org/10.1016/j.toxlet.2012.02.001
Barber CM, Isbister GK, Hodgson WC. Solving the 'Brown Snake Paradox': in Vitro Characterisation of Australasian Snake Presynaptic Neurotoxin Activity. Toxicol Lett. 2012 May 5;210(3):318-23. PubMed PMID: 22343038.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Solving the 'Brown snake paradox': in vitro characterisation of Australasian snake presynaptic neurotoxin activity. AU - Barber,Carmel M, AU - Isbister,Geoffrey K, AU - Hodgson,Wayne C, Y1 - 2012/02/10/ PY - 2011/11/17/received PY - 2012/02/01/revised PY - 2012/02/01/accepted PY - 2012/2/21/entrez PY - 2012/2/22/pubmed PY - 2012/5/19/medline SP - 318 EP - 23 JF - Toxicology letters JO - Toxicol Lett VL - 210 IS - 3 N2 - Pseudonaja textilis (Eastern Brown snake) and Oxyuranus scutellatus scutellatus (Coastal taipan) are clinically important Australian elapid snakes, whose potent venoms contain the presynaptic (β) neurotoxins, textilotoxin and taipoxin, respectively, and a number of postsynaptic neurotoxins. However, while taipan envenoming frequently results in neurotoxicity, Brown snake envenoming causes an isolated coagulopathy and neurotoxicity is rare. This phenomenon is called the 'Brown snake paradox'. This study compared the pharmacology of both venoms and their respective presynaptic neurotoxins to investigate this phenomenon. From size-exclusion high performance liquid chromatography (HPLC) analysis textilotoxin represents a significantly smaller proportion (5.7%) of P. textilis venom compared to taipoxin in O. s. scutellatus venom (20.4%). In the chick biventer cervicis nerve-muscle (CBCNM) preparation both venoms caused concentration-dependent neurotoxicity, with P. textilis venom being significantly more potent than O. s. scutellatus venom. Conversely, taipoxin was significantly more potent than textilotoxin when compared at the same concentration. Textilotoxin only partially contributed to the overall neurotoxicity of P. textilis venom, while taipoxin accounted for the majority of the neurotoxicity of O. s. scutellatus venom in the CBCNM preparation. Compared with taipoxin, textilotoxin is less potent and constitutes a smaller proportion of the venom. This is likely to be the reason for the absence of neurotoxicity in envenomed humans thus explaining the 'Brown snake paradox'. SN - 1879-3169 UR - https://www.unboundmedicine.com/medline/citation/22343038/Solving_the_'Brown_snake_paradox':_in_vitro_characterisation_of_Australasian_snake_presynaptic_neurotoxin_activity_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0378-4274(12)00055-0 DB - PRIME DP - Unbound Medicine ER -