Effect of Exercise on micro-Opioid Receptor Expression in the Rostral Ventromedial Medulla in Neuropathic Pain Rat Model
Annals of Rehabilitation Medicine
;
: 331-339, 2015.
Article
in English
| WPRIM
| ID: wpr-153689
ABSTRACT
OBJECTIVE:
To investigate the effects of aerobic exercise on neuropathic pain and verify whether regular treadmill exercise alters opioid receptor expression in the rostral ventral medulla (RVM) in a neuropathic pain rat model.METHODS:
Thirty-two male Sprague-Dawley rats were used in the study. All rats were divided into 3 groups, i.e., group A, sham group (n=10); group B, chronic constriction injury (CCI) group (n=11); and group C, CCI+exercise group (n=11). Regular treadmill exercise was performed for 30 minutes a day, 5 days a week, for 4 weeks at the speed of 8 m/min for 5 minutes, 11 m/min for 5 minutes, and 22 m/min for 20 minutes. Withdrawal threshold and withdrawal latency were measured before and after the regular exercise program. Immunohistochemistry and Western blots analyses were performed using antibodies against micro-opioid receptor (MOR).RESULTS:
Body weight of group C was the lowest among all groups. Withdrawal thresholds and withdrawal latencies were increased with time in groups B and C. There were significant differences of withdrawal thresholds between group B and group C at 1st, 2nd, 3rd, and 4th weeks after exercise. There were significant differences of withdrawal latencies between group B and group C at 3rd and 4th weeks after exercise. MOR expression of group C was significantly decreased, as compared to that of group B in the RVM and spinal cord.CONCLUSION:
In neuropathic pain, exercise induced analgesia could be mediated by desensitization of central MOR by endogenous opioids, leading to the shift of RVM circuitry balance to pain inhibition.
Full text:
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Index:
WPRIM (Western Pacific)
Main subject:
Spinal Cord
/
Body Weight
/
Medulla Oblongata
/
Immunohistochemistry
/
Exercise
/
Blotting, Western
/
Rats, Sprague-Dawley
/
Receptors, Opioid
/
Constriction
/
Models, Animal
Limits:
Animals
/
Humans
/
Male
Language:
English
Journal:
Annals of Rehabilitation Medicine
Year:
2015
Type:
Article
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