Crotoxin from Crotalus durissus terrificus snake venom induces the release of glutamate from cerebrocortical synaptosomes via N and P/Q calcium channels.

Toxicon

Programa de Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. Electronic address:

Published: July 2014

Crotoxin (Crtx), the main toxin in the venom of Crotalus durissus terrificus snake, is a heterodimer with a basic subunit, CB, and an acidic subunit, CA. CB is a phospholipase A2 that depends on CA to specifically bind to the cell membrane. This toxin acts in the central nervous system (CNS) causing chronic seizure effects and other cytotoxic effects. Here, we report its action on glutamate release in rat cerebral cortex synaptosomes. Aiming at a better understanding of the mechanism of action of Crtx, calcium channel blockers were used and internalization studies were performed in cerebellar granule neurons. Our results show that Crtx induces calcium-dependent glutamate release via N and P/Q calcium channels. In addition, the CB subunit of Crtx is shown to be internalized. This internalization does not depend on the presence of CA subunit neither on the PLA2 activity of CB. A correlation between CB internalization and glutamate release remains to be established.

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http://dx.doi.org/10.1016/j.toxicon.2014.04.008DOI Listing

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