The somatic and autonomic activities of Tityus bahiensis scorpion venom and its isolated fractions.

• Grant number: 16/11319-6
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): September 01, 2016
• Effective date (End): February 28, 2019
• Field of knowledge: Biological Sciences - Pharmacology
• Principal researcher: Edson Antunes
• Grantee: Rita de Cássia de Oliveira Collaço
• Home Institution: Faculdade de Ciências Médicas (FCM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated scholarship(s): 16/23829-9 - Tityus bahiensis scorpion venom and its isolated fractions: an electrophysiological and calcium-imaging study on somatic and autonomic nerve-muscle systems., BE.EP.DR

Abstract

In addition to local effects, scorpion envenomation produces systemic effects predominantly related to massive neurotransmitter release from central and peripheral nervous system. This neurotoxic activity has been attributed to venom-containing peptides that have great specificity and affinity to ion channels, resulting in activation, inactivation, blockade or alterations of its opening/closing mechanisms. Scorpion neurotoxins have been widely used as pharmacological tools to understand the ion channel structure and its physiology, as well as to evaluate its contribution to many diseases such as channelopathy, epilepsy, facial paralysis, muscular diseases, cardiac arrhythmia and pain syndromes, thus offering novel strategies for developing therapeutic drugs. Tityus bahiensis is the major responsible for scorpion stings on São Paulo State (and second more important in Brazil); however, its total venom and isolated fractions remain scarcely studied, especially regarding to the peripheral nervous system and ion channel activation. The aim of this work is to evaluate the activities of T. bahiensis venom and its isolated fractions on (i) different isolated nerve/skeletal muscle preparations under direct and indirect/field stimulations (somatic activity); (ii) rat vas deferens preparation upon to electrical-field stimulation (autonomic activity); (iii) electrophysiological experiments to analyze the resting membrane potential (skeletal and smooth muscle), end-plate potentials (spontaneous and evoked currents), nerve action potential, and perineural waveforms (calcium, sodium and potassium currents); and (iv) evaluation of the individual potassium, sodium and calcium channel currents using voltage-clamp and patch-clamp techniques. The proposed project will afford knowledge of the pre and postsynaptic effects caused by T. bahiensis venom neurotoxins. The results of this work could encourage the study/isolation of molecules with pharmacological potential that may be used as research tools.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

COLLACO, RITA DE CASSIA; HYSLOP, STEPHEN; ROCHA, THALITA; DORCE, VALQUIRIA A. C.; ROWAN, EDWARD G.; ANTUNES, EDSON. Neurotoxicity ofTityus bahiensis(brown scorpion) venom in sympathetic vas deferens preparations and neuronal cells. ARCHIVES OF TOXICOLOGY, v. 94, n. 9 JUN 2020. Web of Science Citations: 0.

COLLACO, RITA DE CASSIA O.; HYSLOP, STEPHEN; DORCE, VALQUIRIA A. C.; ANTUNES, EDSON; ROWAN, EDWARD G. Scorpion venom increases acetylcholine release by prolonging the duration of somatic nerve action potentials. Neuropharmacology, v. 153, p. 41-52, JUL 15 2019. Web of Science Citations: 0.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

COLLAÇO, Rita de Cássia de Oliveira. Tityus bahiensis scorpion venom activities on somatic and autonomic preparations. 2019. 181 f. Doctoral Thesis - Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas.