Estudo dos efeitos vasculares da peçonha de Tityus pachyurus em ratos Wistar

Abstract

Accidents with scorpions affect the entire world, with an incidence of 1.2 million bites with more than 3 thousand fatal cases, being more prevalent in countries with tropical and subtropical climates. Given the clinical importance and frequency of accidents caused by Tityus pachyurus, a species of scorpion distributed mainly in the Magdalena Médio Valley, in Colombia, the extent of the venom of Tityus pachyurus was determined, initially qualitatively evaluating the percentage of irritation (irritation score, IS). HET-CAM, based on three effects observed in the membrane: hemorrhage, lysis of vessels and coagulation of poison on the blood vessels of chicken eggs, where it was determined that the poison is strongly irritating and has vasodilatory capacity on the vascular tone, identified the changes in the percentage of the vascular area of the eggs in the presence VTp, indicating or vasodilator effect itself (average of 10.43%). To quantify the vascular effects of the nipple of T. pachyurus (VTp) in temporary aortic anieses, it was evaluated in an In vitro vivo system, using the isolated organ bath technique. Foram realized cumulative concentration curves vs. It responds to VTp (0.05 μg/ml to 60 μg/ml) with different blockers grouped according to its route of action: endothelial, ação in K+ channels (TEA, 4AP, Glibenclamida), ação in the NO via (L-NAME, ODQ), and ação on muscarinic receptors (ATR). VTp showed a vasodilatory response dependent on both calcium-activated potassium channels (BK) (p = 0.0261) and voltage-dependent potassium channels (Kv) (p = 0.0014) and also on the muscarinic pathway dependent on M₃ receptors (p = 0.0264). The vasodilatory response of venom was reduced mainly by NO blockers: L-NAME (p=0.0100) and ODQ (p=0.0037). The blocking effect of GLIB was not significant (p=0.9907), indicating that the poison is not similar to the ATP-Dependent K+ channels. Finally, we constructed the proposed three-dimensional structure of three VTp molecules (TPA1, TPA2 and TPA3), in order to predict which proteins or receptors could be affected by poison toxins. This work contributes to a better understanding of the mechanism of action of VTp and is expected to contribute to a better understanding of the administration of adequate medical treatments.