Data/hora: 03/06/2024 18:21:46

Provedor de dados: | 56
País: | Brazil
Título: | Anxiolytic effect of methylene blue microinjected into the dorsal periaqueductal gray matter
Autores: | de-Oliveira,R.W.; Guimarães,F.S.
Data: | 1999-12-01
Ano: | 1999
Palavras-chave: | Anxiety; Elevated plus-maze; Nitric oxide; Animal model.
Resumo: | The dorsal periaqueductal gray (DPAG) has been implicated in the behavioral and autonomic expression of defensive reactions. Several results suggest that, along with GABA, glutamate and serotonin, nitric oxide (NO) may play a role in defense reactions mediated by this region. To further investigate this possibility we microinjected methylene blue (MB; 10, 30 or 100 nmol/0.5 µl) into the DPAG of rats submitted to the elevated plus-maze test, an animal model of anxiety. MB has been used as an inhibitor of soluble guanylate cyclase (sGC) to demonstrate cGMP-mediated processes, and there is evidence that NO may exert its biological effects by binding to the heme part of guanylate cyclase, causing an increase in cGMP levels. The results showed that MB (30 nmol) significantly increased the percent of time spent in the open arms (saline = 11.57 ± 1.54, MB = 18.5 ± 2.45, P&amp;lt;0.05) and tended to do the same with the percentage of open arm entries (saline = 25.8 ± 1.97, MB = 33.77 ± 3.07, P&amp;lt;0.10), but did not change the number of enclosed arm entries. The dose-response curve, however, had an inverted U shape. These results indicate that MB, within a limited dose range, has anxiolytic properties when microinjected into the DPAG.
Tipo: | Info:eu-repo/semantics/other
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001200012
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X1999001200012
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.32 n.12 1999
Fonte: | info:eu-repo/semantics/openAccess