Release of gamma-[(3)H]aminobutyric acid in rat brain cortical slices by alpha-scorpion toxin.
In this paper, the effect of the alpha-scorpion toxin tityustoxin (TsTX) in the release of gamma-[(3)H]aminobutyric acid ([(3)H]GABA) from rat brain cortical slices is described. The TsTX-stimulatory effect on the release of [(3)H]GABA was dependent on incubation time and TsTX concentration, having an EC(50) of 0.33 microM. Tetrodotoxin (TTX) completely inhibited the TsTX action on [(3)H]GABA release. The scorpion toxin effect was calcium-dependent and involves P/Q calcium channels. beta-Alanine also induces the release of [(3)H]GABA that was not inhibited by TTX but was additive in the presence of TsTX. The data suggest a neuronal origin for the release of [(3)H]GABA by TsTX.
Nicolato
R
R
Laboratório de Neurofarmacologia, Departamento de Farmacologia, ICB-UFMG, Avenida Antonio Carlos 6627, Pampulha, 31270-901 Belo Horizonte MG, Brazil.
Fernandes
V M V
VM
Moraes-Santos
T
T
Gomez
R S
RS
Prado
M A M
MA
Romano-Silva
M A
MA
Gomez
M V
MV
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects*; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D051381:Rats; D012604:Scorpion Venoms / Q000009:adverse effects*; D026941:Sodium Channel Blockers / Q000494:pharmacology; D015222:Sodium Channels / Q000187:drug effects; D013779:Tetrodotoxin / Q000494:pharmacology; D013997:Time Factors; D014316:Tritium; D015091:beta-Alanine / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D012604:Scorpion Venoms; D026941:Sodium Channel Blockers; D015222:Sodium Channels; D014316:Tritium; D015091:beta-Alanine; C003609:tityustoxin; D013779:Tetrodotoxin; D005680:gamma-Aminobutyric Acid