Comparison the Analgesic Effect of Electeroacupuncture and Tramadol on Writhing Test in Rat

Background: Since the use of electeroacupuncture (EA) may be suitable for animals in veterinary medicine, in present study, analgesia of this technique on control of visceral pain was compared to tramadol effect. Methods: The study was carried in 5 groups of Wistar rats. One group was kept without restriction and drugs (group1) and another group was only restricted (group 2). Acetic acid was intraperitoneally injected in 3 to 5 groups of rats (10 rats each group) and the number of writhes was counted for 40 minutes after acetic acid injection. Group 3 received acetic acid and was kept as control. Tramadol was administered at dose 10 mg/kg intramuscularly in group 4 and rats of group 5 received EA and ST-36 (Zu San Li) and SP-6 (San Yin Jiao) points were stimulated at 1ms, 0.3 and 0.3 Hz, duration, intensity and frequency respectively. The amount of serum cortisol was measured by ELISA kit at end of study. Results: The results shown the mean of writhing was significantly decreased in group 4 and 5 with comparison to group 3. In groups 3, 4 and 5 the mean writhing was 22.3, 3.4 and 3.6 per 10 minutes respectively. The mean of serum cortisol was greater in group 2 than other groups. This mean was significantly was lesser in group 4 and 5 in comparison to control group 3. In other hands, the mean cortisol was 0.7 and 1.16 ng/ml in groups 3, 4 and 5 respectively. Conclusion: Present study shows that tramadol and EA has similar analgesic effect on writhing test in rats.