Hematological changes INDUCED BY Tityus serrulatus VENOM IN RATS

Cusinato, D.A.C.(1), Souza, A.M.(2), Gregório, Z.M.O.(2), Ogawa, K.C.(1), Vasconcelos, F.(1), Arantes, E.C.(1)

(1)Departamento de Física e Química, (2)Departamento de Análises Clínicas Toxicológicas e Bromatológicas, FCFRP, USP, Ribeirão Preto, SP, Brazil.

objectives: The aim of this work was to evaluate the hematological changes induced by Tityus serrulatus venom (TsV), using in vivo and in vitro assays.

Methods and results: Blood was collected from male Wistar rats (6 rats/group, b.w. 100 g)30, 120 and 360 min after the intraperitoneal injection of TsV (500 mg/kg) or 0.9% NaCl (control). The following hematological parameters were determined by standard methods: red blood cell count with a Neubauer hemocytometer using Hayem diluting solution, hemoglobin concentration (Hb) by the cyanmethemoglobin method, packed red blood cell volume or hematocrit(Ht) by the microhematocrit method, and red blood cell indices (mean corpuscular volume – MCV, mean corpuscular hemoglobin – MCH, and mean corpuscular hemoglobin concentration – MCHC). The osmotic fragility (OF) of red blood cells was determined using fresh blood and various concentrations of hypotonic NaCl (0%–0.85%). The median corpuscular fragility (MCF) corresponded to the saline concentration that lysed 50% of the cells. The osmotic fragility test in vitro used blood preincubated with TsV (250 mg/mL)or 0.9% NaCl (control). TsV significantly increased the Ht (44%), Hb (13.9 g/dL) and red blood cell count (5.3x10¹²/L) after 120 min compared to the control values (36.5%, 11.7 g/dLand 4.5x10¹²/L, respectively). A significant decrease in the MCF (in vivo) was observed 120 min (0.40%) and 360 min (0.39%) after TsV injection relative to the control (0.43%). There were no significant changes in the other parameters assayed.

Conclusion: The reduction in MCF may be a consequence of the dehydration induced by TsV. The increase in Ht, Hb and red blood cell count indicated hemoconcentration. Further analyses are necessary to confirm these findings. 

CORRESPONDENCE TO:

Diego Alberto Ciscato Cusinato, Rua General Osório, 782 Apto. 8-A, Ribeirão Preto, SP, CEP: 17-770-000, Brasil, Email: diegocusinato@uol.com.br