Journal of Rafsanjan University of Medical Sciences

Background and Objective: Some studies have shown that different exercises reduce pain in different levels by affecting the levels of opioid. Therefore, we investigated the effect of exercise on pain and morphine-induced analgesia in the formalin test in male mice.

Materials and Methods: In this experimental study, 120 mice were randomly divided into 8 groups according to three different training sessions and uae of  received morphine or saline. The training program was conducted on a treadmill for 30 minutes on the speed of 0.3 meters per second with different slopes. Thirty minutes before starting each exercise, 5 mg of morphine per kg of the animal weight was injected intraperitoneally. Finally, all groups were tested using the formalin test. Data were analyzed using one-way ANOVA and post hoc Tukey test.

Results: A significant reduction was found in response to painful stimuli in the acute phase (0-5 minutes) among the morphine receiving groups (p=0.001). On the other hand, the response to painful stimuli in the chronic pain phase (16-60 min) showed a signification reduction for the morphine receiving groups as well as the exercise group with a positive slope (p=0.015). 

Conclusion: If the intensity of exercise can reach the threshold level required to stimulate the endogenous opioids, it is likely to reduce the feeling of pain. Furthermore, the effect of morphine can not be influenced by the kind of exercise.

Key words: Acute pain, Chronic pain, Exercise, Formalin test, Morphine

Funding: This research was funded by Shiraz University.

Conflict of interest: None declared.

Ethical Approval: The Ethics Committee of Shiraz University of Medical Sciences approved the study.

How to cite this article: Jafari H, Daryanoosh F, Zarifkar A, Ghiasi E, Mohammadi M. The Relationship between Job Effect of Exercise on Pain and Morphine-Induced Analgesia in the Formalin Test in Male Mice, 2013. J Rafsanjan Univ Med Sci 2014 13(2): 97-108 [Farsi]