The role of peripheral cannabinoid receptors type 1 in rats with visceral hypersensitivity induced by chronic restraint stress.
J Neurogastroenterol Motil
; 16(3): 281-90, 2010 Jul.
Article
em En
| MEDLINE
| ID: mdl-20680167
ABSTRACT
BACKGROUND/AIMS:
This study was designed to investigate the possibility that the enhanced nociceptive responsiveness associated with canabonoid type 1 receptors (CB1Rs) and identify its role in mediating visceral hypersensitivity induced by chronic restraint stress.METHODS:
Rats were exposed to daily partial restraint stress or sham partial restraint stress with intraperitoneal injection of the vehicle, CB1R agonist or antagonist for 4 consecutive days. We tested the visceromotor reflex to colorectal distention at day 0 and 5. Reverse-transcription polymerase chain reaction and Western blot were used to assess the expression of CB1Rs.RESULTS:
Intraperitoneal CB1 agonist (ACEA) injection significantly diminished (p < 0.05) the enhanced visceromotor reflex to colorectal distention at day 5 in stressed rats. Change in electromyogram response after ACEA over baseline, at pressure of 40 mmHg (+13.3 +/- 2.2), 60 mmHg (+15.3 +/- 2.8) and 80 mmHg (+17.0 +/- 4.0) were much lower than in the control animals, which were +35.9 +/- 5.1, +41.1 +/- 6.3 and +54.1 +/- 9.6, respectively. Whereas, CB1 antagonist (SR141716A) had an opposite effect. Compared with control group, the change in electromyogram response after SR141716A over baseline was significantly enhanced (p < 0.05) for the distending pressure of 40 mmHg (+56.0 +/- 10.3), 60 mmHg (+74.6 +/- 12.3) and 80 mmHg (+82.9 +/- 11.0), respectively. Reverse-transcription polymerase chain reaction and Western blotting demonstrated the stress-induced up-regulation of colon CB1Rs (p < 0.05).CONCLUSIONS:
Our results suggest there is a key contribution of peripheral CB1Rs involved in the maintenance of visceral hyperalgesia after repeated restraint stress, providing a novel mechanism for development of peripheral visceral sensitization.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
J Neurogastroenterol Motil
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
China
País de publicação:
COREA DEL SUR
/
CORÉIA DO SUL
/
KR
/
SOUTH KOREA