Produção Nacional
Revisado por pares
Effects of α-scorpion toxin, tityustoxin on the release of [3H] dopamine of rat brain prefrontal cortical slices
2003; Elsevier BV; Volume: 44; Issue: 2 Linguagem: Inglês
10.1016/s0197-0186(03)00114-1
ISSN1872-9754
AutoresVirginia Maria Vidigal Fernandes, André Ricardo Massensini, Marco A. M. Prado, Marco Aurélio Romano‐Silva, Tasso Moraes-Santos, Marcus V. Gomez,
Tópico(s)Nicotinic Acetylcholine Receptors Study
ResumoThe effect of tityustoxin (TsTX) on the release of [3H] dopamine in rat brain prefrontal cortical slices was investigated. The stimulatory effect of TsTX was dependent on incubation time and TsTX concentration with an EC50 of 0.05 μM. The release of [3H] dopamine stimulated by TsTX is dependent of Na+ channels and thus, was completely, inhibited by tetrodotoxin. Tityustoxin-induced release of [3H] dopamine was not blocked by ethylene glycol-bis(β-aminoethyl) ether (EGTA) and thus was independent of extracellular calcium. However, [3H] dopamine release induced by TsTX was inhibited by 52% by BAPTA, a calcium chelator. Moreover, dantrolene (100 μM) and tetracaine (500 μM) partially inhibited by 38 and 29%, respectively, the tityustoxin-induced release of [3H] dopamine from prefrontal cortical slices suggesting a role from intracellular calcium increase. In conclusion, part of the TsTX-induced release [3H] dopamine may be due to an effect of the toxin on the reversal of the dopamine transporter (DAT), but the majority of the toxin stimulated release of [3H] dopamine involves the mobilization of intracellular calcium stores.
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