Transient ophthalmoplegia following envenomation by the scorpion
            <i>Mesobuthus eupeus</i>

Sadeghian, Hamid

doi:10.1212/01.wnl.0000044158.90246.9f

Cited by 18 publications

(10 citation statements)

References 6 publications

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“…Several genera of this family -such as Tityus, Centruroides, Androctonus and Parabuthus -are known for their strong venom neurotoxins (19). Mesobuthus eupeus is found in the Middle East and Central Asia and is responsible for a large number of envenomations in these regions (19,20).…”

Section: Discussionmentioning

confidence: 99%

Comparison of two purified toxic fractions from Mesobuthus eupeus scorpion venom

Shirmardi¹,

Shamsaei²,

Ghanei³

et al. 2010

J. Venom. Anim. Toxins incl. Trop. Dis

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Abstract:Iranian scorpions belong mainly to the Buthidae and Scorpionidae families, distributed into 16 genera and 25 species. In Iran, similar to other parts of the world, there are a few known species of scorpions responsible for severe envenoming; amongst which Mesobuthus eupeus is the most common. Its venom contains several toxin fractions that may affect the ion channel. In the present study purification, labeling and biological evaluation of M. eupeus venom are described. For separation, soluble venom was loaded on a chromatography column packed with Sephadex G-50 gel. Subsequently, the fractions were collected according to UV absorption at a wavelength of 280 nm. Toxic fraction (F3) was loaded on an anionic ion exchanger resin and then on a cationic resin. Finally, toxic subfractions F3.1.6 and F3.1.9 were labeled with 99m Tc and injected into normal mice to distinguish excretion pathway. The venom toxic fraction was successfully obtained in its purified form. Radiolabeling of toxic fractions was performed at high specific activity with radiochemical purity of more than 97 and 95% respectively for F3.1.6 and F3.1.9. Biodistribution studies in normal mice with two toxic fractions usually show rapid clearance of the compounds from blood and tissue except for kidneys. Since tissue distribution studies are very important for clinical purpose, the present findings suggest that 99m Tc labeling of venom is a useful tool for in vivo studies and comprises an excellent approach to monitoring the process of biodistribution and kinetics of toxins.

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Section: Discussionmentioning

confidence: 99%

Comparison of two purified toxic fractions from Mesobuthus eupeus scorpion venom

Shirmardi¹,

Shamsaei²,

Ghanei³

et al. 2010

J. Venom. Anim. Toxins incl. Trop. Dis

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“…Toxins that bind K + channels block the flow of K + ions through the channel, preventing the membrane from returning to its resting potential after depolarization [8], [9]. The synergistic effect of these toxins is hyper-excitability of nerve and muscle cells that can cause a wide range of physiological malfunction [10], [11], [12], [13]. Even when buthid stings are not fatal, humans report excruciating pain that may last from several hours to days.…”

Section: Introductionmentioning

confidence: 99%

Isolation and Characterization of CvIV4: A Pain Inducing α- Scorpion Toxin

et al. 2011

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BackgroundAmong scorpion species, the Buthidae produce the most deadly and painful venoms. However, little is known regarding the venom components that cause pain and their mechanism of action. Using a paw-licking assay (Mus musculus), this study compared the pain-inducing capabilities of venoms from two species of New World scorpion (Centruroides vittatus, C. exilicauda) belonging to the neurotoxin-producing family Buthidae with one species of non-neurotoxin producing scorpion (Vaejovis spinigerus) in the family Vaejovidae. A pain-inducing α-toxin (CvIV4) was isolated from the venom of C. vittatus and tested on five Na+ channel isoforms.Principal Findings C. vittatus and C. exilicauda venoms produced significantly more paw licking in Mus than V. spinigerus venom. CvIV4 produced paw licking in Mus equivalent to the effects of whole venom. CvIV4 slowed the fast inactivation of Nav1.7, a Na+ channel expressed in peripheral pain-pathway neurons (nociceptors), but did not affect the Nav1.8-based sodium currents of these neurons. CvIV4 also slowed the fast inactivation of Nav1.2, Nav1.3 and Nav1.4. The effects of CvIV4 are similar to Old World α-toxins that target Nav1.7 (AahII, BmK MI, LqhIII, OD1), however the primary structure of CvIV4 is not similar to these toxins. Mutant Nav1.7 channels (D1586A and E1589Q, DIV S3–S4 linker) reduced but did not abolish the effects of CvIV4.ConclusionsThis study: 1) agrees with anecdotal evidence suggesting that buthid venom is significantly more painful than non-neurotoxic venom; 2) demonstrates that New World buthids inflict painful stings via toxins that modulate Na+ channels expressed in nociceptors; 3) reveals that Old and New World buthids employ similar mechanisms to produce pain. Old and New World α-toxins that target Nav1.7 have diverged in sequence, but the activity of these toxins is similar. Pain-inducing toxins may have evolved in a common ancestor. Alternatively, these toxins may be the product of convergent evolution.

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“…Therefore, they are considered medically important arthropods since they cause envenomation by stinging humans, most of the times, to protect themselves (13,30,32). Medically important species belong to the genera Buthus, Parabuthus, Mesobuthus, Tityus, Leiurus, Androctonus, and Centruroides from the Buthidae family (5,19,35,39).…”

Section: Introductionmentioning

confidence: 99%