Tags

Type your tag names separated by a space and hit enter

Geographical venom variations of the Southeast Asian monocled cobra (Naja kaouthia): venom-induced neuromuscular depression and antivenom neutralization.
Comp Biochem Physiol C Toxicol Pharmacol 2016 Jul-Aug; 185-186:77-86CB

Abstract

The Southeast Asian monocled cobras (Naja kaouthia) exhibit geographical variations in their venom proteomes, especially on the composition of neurotoxins. This study compared the neuromuscular depressant activity of the venoms of N. kaouthia from Malaysia (NK-M), Thailand (NK-T) and Vietnam (NK-V), and the neutralization of neurotoxicity by a monospecific antivenom. On chick biventer cervicis nerve-muscle preparation, all venoms abolished the indirect twitches, with NK-T venom being the most potent (shortest t90, time to 90% twitch inhibition), followed by NK-V and NK-M. Acetylcholine and carbachol failed to reverse the blockade, indicating irreversible/pseudo-irreversible post-synaptic neuromuscular blockade. KCl restored the twitches variably (NK-M preparation being the least responsive), consistent with different degree of muscle damage. The findings support that NK-T venom has the most abundant curarimimetic alpha-neurotoxins, while NK-M venom contains more tissue-damaging cytotoxins. Pre-incubation of tissue with N. kaouthia monovalent antivenom (NKMAV) prevented venom-induced twitch depression, with the NK-T preparation needing the largest antivenom dose. NKMAV added after the onset of neuromuscular depression could only halt the inhibitory progression but failed to restore full contraction. The findings highlight the urgency of early antivenom administration to sequester as much circulating neurotoxins as possible, thereby hastening toxin elimination from the circulation. In envenomed mice, NKMAV administered upon the first neurological sign neutralized the neurotoxic effect, with the slowest full recovery noticed in the NK-T group. This is consistent with the high abundance of neurotoxins in the NK-T venom, implying that a larger amount or repeated dosing of NKMAV may be required in NK-T envenomation.

Authors+Show Affiliations

Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia. Electronic address: tanchoohock@gmail.com.Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.

Pub Type(s)

Comparative Study
Journal Article

Language

eng

PubMed ID

26972756

Citation

Tan, Kae Yi, et al. "Geographical Venom Variations of the Southeast Asian Monocled Cobra (Naja Kaouthia): Venom-induced Neuromuscular Depression and Antivenom Neutralization." Comparative Biochemistry and Physiology. Toxicology & Pharmacology : CBP, vol. 185-186, 2016, pp. 77-86.
Tan KY, Tan CH, Sim SM, et al. Geographical venom variations of the Southeast Asian monocled cobra (Naja kaouthia): venom-induced neuromuscular depression and antivenom neutralization. Comp Biochem Physiol C Toxicol Pharmacol. 2016;185-186:77-86.
Tan, K. Y., Tan, C. H., Sim, S. M., Fung, S. Y., & Tan, N. H. (2016). Geographical venom variations of the Southeast Asian monocled cobra (Naja kaouthia): venom-induced neuromuscular depression and antivenom neutralization. Comparative Biochemistry and Physiology. Toxicology & Pharmacology : CBP, 185-186, pp. 77-86. doi:10.1016/j.cbpc.2016.03.005.
Tan KY, et al. Geographical Venom Variations of the Southeast Asian Monocled Cobra (Naja Kaouthia): Venom-induced Neuromuscular Depression and Antivenom Neutralization. Comp Biochem Physiol C Toxicol Pharmacol. 2016;185-186:77-86. PubMed PMID: 26972756.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Geographical venom variations of the Southeast Asian monocled cobra (Naja kaouthia): venom-induced neuromuscular depression and antivenom neutralization. AU - Tan,Kae Yi, AU - Tan,Choo Hock, AU - Sim,Si Mui, AU - Fung,Shin Yee, AU - Tan,Nget Hong, Y1 - 2016/03/10/ PY - 2015/12/18/received PY - 2016/03/06/revised PY - 2016/03/09/accepted PY - 2016/3/15/entrez PY - 2016/3/15/pubmed PY - 2017/2/18/medline KW - Antivenom KW - Challenge-rescue assay KW - Chick biventer-cervicis nerve-muscle preparation KW - Naja kaouthia KW - Reversibility KW - Venom-induced neurotoxicity SP - 77 EP - 86 JF - Comparative biochemistry and physiology. Toxicology & pharmacology : CBP JO - Comp. Biochem. Physiol. C Toxicol. Pharmacol. VL - 185-186 N2 - The Southeast Asian monocled cobras (Naja kaouthia) exhibit geographical variations in their venom proteomes, especially on the composition of neurotoxins. This study compared the neuromuscular depressant activity of the venoms of N. kaouthia from Malaysia (NK-M), Thailand (NK-T) and Vietnam (NK-V), and the neutralization of neurotoxicity by a monospecific antivenom. On chick biventer cervicis nerve-muscle preparation, all venoms abolished the indirect twitches, with NK-T venom being the most potent (shortest t90, time to 90% twitch inhibition), followed by NK-V and NK-M. Acetylcholine and carbachol failed to reverse the blockade, indicating irreversible/pseudo-irreversible post-synaptic neuromuscular blockade. KCl restored the twitches variably (NK-M preparation being the least responsive), consistent with different degree of muscle damage. The findings support that NK-T venom has the most abundant curarimimetic alpha-neurotoxins, while NK-M venom contains more tissue-damaging cytotoxins. Pre-incubation of tissue with N. kaouthia monovalent antivenom (NKMAV) prevented venom-induced twitch depression, with the NK-T preparation needing the largest antivenom dose. NKMAV added after the onset of neuromuscular depression could only halt the inhibitory progression but failed to restore full contraction. The findings highlight the urgency of early antivenom administration to sequester as much circulating neurotoxins as possible, thereby hastening toxin elimination from the circulation. In envenomed mice, NKMAV administered upon the first neurological sign neutralized the neurotoxic effect, with the slowest full recovery noticed in the NK-T group. This is consistent with the high abundance of neurotoxins in the NK-T venom, implying that a larger amount or repeated dosing of NKMAV may be required in NK-T envenomation. SN - 1532-0456 UR - https://www.unboundmedicine.com/medline/citation/26972756/Geographical_venom_variations_of_the_Southeast_Asian_monocled_cobra__Naja_kaouthia_:_venom_induced_neuromuscular_depression_and_antivenom_neutralization_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S1532-0456(16)30039-4 DB - PRIME DP - Unbound Medicine ER -