The Pharmacological Effects of Odonthobuthus doriae Scorpion Venom and Its Extracted Fractions on Neuro-Muscular Transmission

The effect of odonthobuthos doriae (o.d) scorpion venom at 0/3, 1 and 3, 10 ug/mlconcentrations were investigated on nerve-muscle transmi ssion, using the twitch tensiontechnique.a concentration of 0.3 ug/ml caused a small change in the twitch height in responseto indirect muscle stimulation, but higher concentrations (1, 3, 10 ug/rnl) caused a transientaugmentation in twitch response followed by a large contracture in the chick biventer cervices(cbq preparation. this effect could be defined as a complex action ofthe venom, predominatelypresynaptic, in which its' effects on postjunctional synapses is also maintained.in order to find out which bioactive fraction could explain the venom effects , the solublecrude venom was partially separated by the gel filtration method, using a sephadex gsocolumn, and four fractions were separated. two of the four purified fractions (o.d f3, o.d f4)were characterized as toxic and their ldsovalues were lower than the crude venom. unlike theo.d fi and o.d f2 fractions, o.d f3 and o.d f4 fractions caused a significant block in the twitchand contracture, in comparison to the control sample . in conclusion, fractions o.d f3 and o.df4 are supposed to be as the biological activ e components of the o.d . venom.