The Role of Peripheral Cannabinoid Receptors Type 1 in Rats With Visceral Hypersensitivity Induced by Chronic Restraint Stress
Journal of Neurogastroenterology and Motility
;
: 281-290, 2010.
Article
in English
| WPRIM
| ID: wpr-79065
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.
Full text:
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Index:
WPRIM (Western Pacific)
Main subject:
Piperidines
/
Pyrazoles
/
Reflex
/
Up-Regulation
/
Salicylamides
/
Blotting, Western
/
Polymerase Chain Reaction
/
Negotiating
/
Colon
/
Irritable Bowel Syndrome
Limits:
Animals
Language:
English
Journal:
Journal of Neurogastroenterology and Motility
Year:
2010
Type:
Article
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