Scorpion Venoms by P. Gopalakrishnakone Lourival D. Possani Elisabeth F. Schwartz & Ricardo C. Rodríguez de la Vega

Author:P. Gopalakrishnakone, Lourival D. Possani, Elisabeth F. Schwartz & Ricardo C. Rodríguez de la Vega
Language: eng
Format: epub
Publisher: Springer Netherlands, Dordrecht

Venezuelan Tityus Toxins Inducing Hemostasis Alterations

For more than 35 years, it has been known that some scorpion venoms can affect mammalian blood coagulation. Envenoming by Centruroides sculpturatus (Longenecker and Longenecker 1981), Buthus tamulus (actually renamed as Mesobuthus tamulus) (Reddy et al. 1972), B. martensii (actually renamed as Mesobuthus martensii) (Song et al. 2005), T. discrepans (D’Suze et al. 2003), and T. falconensis (Guinand et al. 2004) has shown the ability of their venoms to perturb the hemostatic system. Clinical studies of scorpionism from the Northeast, North Central, and West Central region in Venezuela have reported patients with alterations of prothrombin and partial thromboplastin time, developing one of them a digestive hemorrhage (De Sousa et al. 1995; D’Suze et al. 2003; Guinand et al. 2004).

Experimental envenomation with T. discrepans venom suggested the presence of toxins able to induce alveoli fibrin deposition and platelets activation. In vitro studies on plasminogen-rich fibrin plate showed an irregular lysis area surrounding a non-lysed area; this effect was dose dependent (Fig. 5). The non-lysed central area (Fig. 5b, c) suggested the presence of a fibrinolytic inhibitor, which after isolation and characterization was called discreplasminin. The inhibitory activity of discreplasminin is similar to aprotinin (Brazón et al. 2009). The lysed area on the plasminogen-rich fibrin plates suggested the presence of fibrinolytic compounds with an activity similar to that of tissue plasminogen activator (t-PA). The fibrinolytic activity could be associated with the anticoagulant effect observed in scorpionism victims with Tityus species (D’Suze et al. 2003; Guinand et al. 2004).

Fig. 5 Fibrinolytic activity of Tityus discrepans whole venom. Fibrinolytic activity of T. discrepans venom (TdV) using plasminogen-rich fibrin plate. (a) TdV (30 μg/10 μL). (b) TdV(100 μg/10 μL). (c) TdV (300 μg/10 μL). (d) t-PA (tissue plasminogen activator – 0.1 μg/10 μL)

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