Sodium currents mediated by voltage-sensitive sodium channels in normal and scorpion toxin-resistant neuroblastoma cells were measured using a giga-ohm seal recording method in the whole cell patch configuration. The voltage and time dependence of sodium currents were similar in normal and mutant cell lines. Half-maximal activation occurred for test depolarizations in the range of -7 to -11 mV....

he present study aimed to develop a method to record circadian patterns of electroretinogram (ERG) and electromyogram (EMG) simultaneously in unrestrained Egyptian yellow fat-tailed scorpion Androctonus australis under different light regimes. A specially designed aluminum "jacket" was properly fixed on the scorpion allowing its free movement during recording. The lightjacket extends along the ...

Scorpion stings are very frequent in Tunisia; yet a method for evaluating envenoming severity and consequently victim treatment, has never been adequately established nor has its efficiency been properly evaluated. Indeed, a management of envenomed patients requires the optimization of envenoming antivenom immunotherapy. This task requires either, an accurate evaluation of toxicokinetic paramet...

Scorpion venoms are complex polypeptide mixtures, the ion channel blockers and antimicrobial peptides being the best studied components. The coagulopathic properties of scorpion venoms are poorly studied and the data about substances exhibiting these properties are very limited. During research on the Heterometrus laoticus scorpion venom, we have isolated low-molecular compounds with anticoagul...

Excitation-contraction coupling was characterized in scorpion striated muscle fibers using standard microelectrode techniques as employed in studies on vertebrate skeletal muscle. The action potential of scorpion muscle consists of two phases of regenerative activity. A relatively fast, overshooting initial spike is followed by a prolonged after-discharge of smaller, repetitive spikes. This aft...

Predators feeding on toxic prey may evolve physiological resistance to the preys' toxins. Grasshopper mice (Onychomys spp.) are voracious predators of scorpions in North American deserts. Two species of grasshopper mice (Onychomys torridus and Onychomys arenicola) are broadly sympatric with two species of potentially lethal bark scorpion (Centruroides exilicauda and Centruroides vittatus) in th...

Voltage sensing by voltage-gated sodium channels determines the electrical excitability of cells, but the molecular mechanism is unknown. ß-scorpion toxins bind specifically to neurotoxin receptor site 4 and induce a negative shift in the voltage dependence of activation through a voltagesensor trapping mechanism. Kinetic analysis showed that β-scorpion toxin binds to the resting state and subs...

scorpion bite is a common health problem in many parts of the world, including the iran’s tropics. there are thousands of cases and a number of deaths due to scorpion bite every year in the country. the present study aims to provide further data regarding the details, complications and outcomes of scorpion bite cases referring to razi hospital, ahwaz, from march 2011 to april 2012. a total of 2...

SUMMARY Two web-based applications to analyze amino acids three-dimensional (3D) local environment within protein structures-SCORPION and FORMIGA-are presented. SCORPION and FORMIGA produce a graphical presentation for simple statistical data showing the frequency of residue occurrence within a given sphere (defined here as the 3D contacts). The center of that sphere is placed at the Calpha and...