An alternative micromethod to access the procoagulant activity of Bothrops jararaca venom and the efficacy of antivenom

Autor(es)

Oguiura, N. ^[1] ; Kapronezai, J. ^[1] ; Ribeiro, T. ^[1] ; Rocha, M. M. T. ^[2] ; Medeiros, C. R. ^[3] ; Marcelino, J. R. ^[4] ; Prezoto, B. C. ^[5]

Afiliação do(s) autor(es)

^[1] Butantan Inst, Ecol & Evolut Lab, BR-05503900 Sao Paulo - Brazil

^[2] Butantan Inst, Lab Herpetol, BR-05503900 Sao Paulo - Brazil

^[3] Vital Brasil Hosp, Butantan Inst, BR-05503900 Sao Paulo - Brazil

^[4] Butantan Inst, Serv Immunol, BR-05503900 Sao Paulo - Brazil

^[5] Butantan Inst, Pharmacol Lab, BR-05503900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Toxicon; v. 90, p. 148-154, NOV 2014.
• Citações Web of Science: 7

Resumo

The assessment of the capacity of antivenoms to neutralize the lethal activity of snake venoms still relies largely on traditional rodent lethality assay (LD50). However, adequately validated in vitro tests should be introduced for assessing antivenom neutralizing capacity in plasma of immunized horses as well as for in-process quality control. The dynamic of fibrin formation in recalcified avian plasma samples is extremely slow, when compared to that presented by mammalian plasmas. In this study, we present one new coagulant assay, by performing dose-response curve after plotting the clotting time (CT) parameter of the ROTEM profile of recalcified chicken plasma samples (target) against semi-logarithmic doses of Bothrops jararaca venom (agonist), either in absence or in presence of the semi-logarithmic doses of anti-bothropic serum (ABS) (antagonist). The mean coagulant dose 50% (CD50) was defined as the quantity of venom (in mu g) which reduces CT to 900 s, between minimum and maximum responses. The CT induced by 5CD(50) of the venom was used as the control for calculating the effective dose (ED) of each batch of ABS. ED was defined as the ABS dose (nanoliters, nL) at which CT induced by one amount of venom corresponding to 5CD(50) is displaced to the maximum threshold (1800 s). Five batches of the ABS, previously assayed for their lethality neutralizing activity (ED50) were assayed. The correlation coefficient (r) between both in vitro (ED) and in vivo (ED50) values was 0.87 (p value < 0.05). We propose this micro method as highly sensitive for characterization and quantification of possible procoagulant activity of small doses of snake venoms (nanograms) and for detecting small doses (nanoliters) of specific antibodies against this effect in little volume samples of biological fluids. (C) 2014 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 10/08580-8 - Defensinas em serpentes: atividade antibiótica e análise genômica comparativa
• Beneficiário: Nancy Oguiura
• Modalidade de apoio: Auxílio à Pesquisa - Regular