Effect of repeated stress on novelty-induced antinociception in rats
Braz. j. med. biol. res
; 34(2): 241-244, Feb. 2001.
Article
em En
| LILACS
| ID: lil-281602
Biblioteca responsável:
BR1.1
RESUMO
There is extensive evidence that acute stress induces an analgesic response in rats. On the other hand, repeatedly stressed animals may present the opposite effect, i.e., hyperalgesia. Furthermore, exposure to novelty is known to induce antinociception. The effects of repeated restraint stress on nociception after exposure to novelty, as measured by the tail-flick latency (TFL), were studied in adult male rats. The animals were stressed by restraint 1 h daily, 5 days a week for 40 days. The control group was not submitted to restraint. Nociception was assessed with a tail-flick apparatus. After being familiarized with the TFL apparatus, each group was subdivided into two other groups, i.e., with or without novelty. Animals were subjected to the TFL measurement twice. For the animals exposed to novelty, the first TFL measurement was made immediately before, and the second 2 min after a 2-min exposure to a new environment. While the control group presented an increased TFL after exposure to a novel environment, chronically stressed animals did not show this effect. These results suggest that repeated restraint stress induces an alteration in the nociceptive response, perhaps as a result of an alteration in endogenous opioids in these animals
Texto completo:
1
Coleções:
01-internacional
Base de dados:
LILACS
Assunto principal:
Estresse Psicológico
/
Comportamento Exploratório
/
Analgesia
Tipo de estudo:
Observational_studies
Limite:
Animals
Idioma:
En
Revista:
Braz. j. med. biol. res
Assunto da revista:
BIOLOGIA
/
MEDICINA
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Brasil