Tags

Type your tag names separated by a space and hit enter

The effects of antivenom on the in vitro neurotoxicity of venoms from the taipans Oxyuranus scutellatus, Oxyuranus microlepidotus and Oxyuranus scutellatus canni.
Toxicon. 1999 Dec; 37(12):1771-8.T

Abstract

The venoms of the inland (Oxyuranus microlepidotus), coastal (O. scutellatus) and Papuan (O. s. canni) taipans are among the most potent in the world. The present study compared the in vitro neurotoxic effects of these venoms and the protective effects of taipan antivenom. Venom (10 microg/ml) from all three snakes abolished nerve-mediated twitches of the chick biventer cervicis muscle preparation with the following rank order of potency (based on the time taken to inhibit 90% of the twitch response; t90): O. microlepidotus (27+/-3 min) > O. scutellatus (42+/-3 min) = O. S. canni (48+/-5 min). This inhibitory effect of all three venoms was primarily postsynaptic in origin as evidenced by the inhibition of responses to exogenous acetylcholine (ACh; 1 mM) and carbachol (CCh; 20 microM), but not potassium chloride (40 mM). In contrast, the presynaptic neurotoxins taipoxin (3 microg/ml) and paradoxin (3 microg/ml) abolished nerve-mediated twitches without producing a significant effect on contractile responses to exogenous agonists. Prior incubation of the tissue with taipan antivenom (1 unit/ml for 10 min) markedly attenuated the inhibitory effects of taipoxin (3 microg/ml) and paradoxin (3 microg/ml), as well as O. scutellatus (10 microg/ml) and O. s. canni (10 microg/ml) venom. However, in the presence of antivenom, O. microlepidotus venom (10 microg/ml) still abolished nerve-mediated twitches and responses to ACh and CCh. The results of the current study indicate that taipan antivenom, raised against O. scutellatus venom, is effective, in vitro, against the neurotoxic effects of venom from the Papuan and coastal taipans, as well as the presynaptic effects of venom from the inland taipan. However, the antivenom appears less effective against the postsynaptic effects of the latter. It is possible that inland taipan venom contains a component not neutralised by the antivenom which may contribute to the extreme potency of this venom.

Authors+Show Affiliations

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

Pub Type(s)

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

Language

eng

PubMed ID

10519654

Citation

Crachi, M T., et al. "The Effects of Antivenom On the in Vitro Neurotoxicity of Venoms From the Taipans Oxyuranus Scutellatus, Oxyuranus Microlepidotus and Oxyuranus Scutellatus Canni." Toxicon : Official Journal of the International Society On Toxinology, vol. 37, no. 12, 1999, pp. 1771-8.
Crachi MT, Hammer LW, Hodgson WC. The effects of antivenom on the in vitro neurotoxicity of venoms from the taipans Oxyuranus scutellatus, Oxyuranus microlepidotus and Oxyuranus scutellatus canni. Toxicon. 1999;37(12):1771-8.
Crachi, M. T., Hammer, L. W., & Hodgson, W. C. (1999). The effects of antivenom on the in vitro neurotoxicity of venoms from the taipans Oxyuranus scutellatus, Oxyuranus microlepidotus and Oxyuranus scutellatus canni. Toxicon : Official Journal of the International Society On Toxinology, 37(12), 1771-8.
Crachi MT, Hammer LW, Hodgson WC. The Effects of Antivenom On the in Vitro Neurotoxicity of Venoms From the Taipans Oxyuranus Scutellatus, Oxyuranus Microlepidotus and Oxyuranus Scutellatus Canni. Toxicon. 1999;37(12):1771-8. PubMed PMID: 10519654.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The effects of antivenom on the in vitro neurotoxicity of venoms from the taipans Oxyuranus scutellatus, Oxyuranus microlepidotus and Oxyuranus scutellatus canni. AU - Crachi,M T, AU - Hammer,L W, AU - Hodgson,W C, PY - 1999/10/16/pubmed PY - 1999/10/16/medline PY - 1999/10/16/entrez SP - 1771 EP - 8 JF - Toxicon : official journal of the International Society on Toxinology JO - Toxicon VL - 37 IS - 12 N2 - The venoms of the inland (Oxyuranus microlepidotus), coastal (O. scutellatus) and Papuan (O. s. canni) taipans are among the most potent in the world. The present study compared the in vitro neurotoxic effects of these venoms and the protective effects of taipan antivenom. Venom (10 microg/ml) from all three snakes abolished nerve-mediated twitches of the chick biventer cervicis muscle preparation with the following rank order of potency (based on the time taken to inhibit 90% of the twitch response; t90): O. microlepidotus (27+/-3 min) > O. scutellatus (42+/-3 min) = O. S. canni (48+/-5 min). This inhibitory effect of all three venoms was primarily postsynaptic in origin as evidenced by the inhibition of responses to exogenous acetylcholine (ACh; 1 mM) and carbachol (CCh; 20 microM), but not potassium chloride (40 mM). In contrast, the presynaptic neurotoxins taipoxin (3 microg/ml) and paradoxin (3 microg/ml) abolished nerve-mediated twitches without producing a significant effect on contractile responses to exogenous agonists. Prior incubation of the tissue with taipan antivenom (1 unit/ml for 10 min) markedly attenuated the inhibitory effects of taipoxin (3 microg/ml) and paradoxin (3 microg/ml), as well as O. scutellatus (10 microg/ml) and O. s. canni (10 microg/ml) venom. However, in the presence of antivenom, O. microlepidotus venom (10 microg/ml) still abolished nerve-mediated twitches and responses to ACh and CCh. The results of the current study indicate that taipan antivenom, raised against O. scutellatus venom, is effective, in vitro, against the neurotoxic effects of venom from the Papuan and coastal taipans, as well as the presynaptic effects of venom from the inland taipan. However, the antivenom appears less effective against the postsynaptic effects of the latter. It is possible that inland taipan venom contains a component not neutralised by the antivenom which may contribute to the extreme potency of this venom. SN - 0041-0101 UR - https://www.unboundmedicine.com/medline/citation/10519654/The_effects_of_antivenom_on_the_in_vitro_neurotoxicity_of_venoms_from_the_taipans_Oxyuranus_scutellatus_Oxyuranus_microlepidotus_and_Oxyuranus_scutellatus_canni_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S004101019900118X DB - PRIME DP - Unbound Medicine ER -