Data/hora: 28/05/2024 16:48:50

Provedor de dados: | 56
País: | Brazil
Título: | Hyperalgesic effect induced by barbiturates, midazolam and ethanol: pharmacological evidence for GABA-A receptor involvement
Data: | 1997-02-01
Ano: | 1997
Palavras-chave: | Barbiturates; Midazolam; Ethanol; Picrotoxin; Hyperalgesia; GABA-A receptor.
Resumo: | The involvement of GABA-A receptors in the control of nociception was studied using the tail-flick test in rats. Non-hypnotic doses of the barbiturates phenobarbital (5-50 mg/kg), pentobarbital (17-33 mg/kg), and thiopental (7.5-30 mg/kg), of the benzodiazepine midazolam (10 mg/kg) or of ethanol (0.4-1.6 g/kg) administered by the systemic route reduced the latency for the tail-flick response, thus inducing a 'hyperalgesic' state in the animals. In contrast, non-convulsant doses of the GABA-A antagonist picrotoxin (0.12-1.0 mg/kg) administered systemically induced an increase in the latency for the tail-flick response, therefore characterizing an 'antinociceptive' state. Previous picrotoxin (0.12 mg/kg) treatment abolished the hyperalgesic state induced by effective doses of the barbiturates, midazolam or ethanol. Since phenobarbital, midazolam and ethanol reproduced the described hyperalgesic effect of GABA-A-specific agonists (muscimol, THIP), which is specifically antagonized by the GABA-A antagonist picrotoxin, our results suggest that GABA-A receptors are tonically involved in the modulation of nociception in the rat central nervous system
Tipo: | Info:eu-repo/semantics/other
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000200015
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X1997000200015
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.30 n.2 1997
Fonte: | info:eu-repo/semantics/openAccess