Neuromuscular Activity of Micrurus laticollaris (Squamata: Elapidae) Venom in Vitro
| Autor: | Rafael Stuani Floriano, Cháriston André Dal Belo, Alejandro Carbajal-Saucedo, Alejandro Alagón, Alejandro Olvera-Rodríguez, Léa Rodrigues-Simioni |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Male
neuromuscular preparations Health Toxicology and Mutagenesis Neuromuscular Junction lcsh:Medicine Venom Biology Pharmacology In Vitro Techniques Receptors Nicotinic Micrurus laticollaris Toxicology Synaptic Transmission Neuromuscular junction Article Membrane Potentials Mice medicine Animals Elapidae Muscle Skeletal snake venom presynaptic action postsynaptic action Coral snake Elapid Venoms Neuromuscular Blockade lcsh:R biochemical phenomena metabolism and nutrition biology.organism_classification Resting potential Blockade Phrenic Nerve medicine.anatomical_structure Snake venom Anesthesia Chickens Acetylcholine medicine.drug |
| Zdroj: | Toxins, Vol 6, Iss 1, Pp 359-370 (2014) Toxins Toxins; Volume 6; Issue 1; Pages: 359-370 |
| ISSN: | 2072-6651 |
| Popis: | In this work, we have examined the neuromuscular activity of Micrurus laticollaris (Mexican coral snake) venom (MLV) in vertebrate isolated nerve-muscle preparations. In chick biventer cervicis preparations, the MLV induced an irreversible concentration- and time-dependent (1–30 µg/mL) neuromuscular blockade, with 50% blockade occurring between 8 and 30 min. Muscle contractures evoked by exogenous acetylcholine were completely abolished by MLV, whereas those of KCl were also significantly altered (86% ± 11%, 53% ± 11%, 89% ± 5% and 89% ± 7% for one, three, 10 and 30 µg of venom/mL, respectively; n = 4; p < 0.05). In mouse phrenic nerve-diaphragm preparations, MLV (1–10 µg/mL) promoted a slight increase in the amplitude of twitch-tension (3 µg/mL), followed by neuromuscular blockade (n = 4); the highest concentration caused complete inhibition of the twitches (time for 50% blockade = 26 ± 3 min), without exhibiting a previous neuromuscular facilitation. The venom (3 µg/mL) induced a biphasic modulation in the frequency of miniature end-plate potentials (MEPPs)/min, causing a significant increase after 15 min, followed by a decrease after 60 min (from 17 ± 1.4 (basal) to 28 ± 2.5 (t15) and 12 ± 2 (t60)). The membrane resting potential of mouse diaphragm preparations pre-exposed or not to d-tubocurarine (5 µg/mL) was also significantly less negative with MLV (10 µg/mL). Together, these results indicate that M. laticollaris venom induces neuromuscular blockade by a combination of pre- and post-synaptic activities. |
| Databáze: | OpenAIRE |
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