Electroacupuncture alleviates stress-induced visceral hypersensitivity through an opioid system in rats

Figure 5 Electroacupuncture treatment attenuated the abdominal withdrawal reflex scores and electromyographic activities. Electroacupuncture (EA) treatments were delivered for 30 min within 24 h after termination of last stressor. For sham EA group, the needle set was inserted into the ST-36 but no electrical stimulation was applied. A: The effects of stress exposure and EA treatment on abdominal withdrawal reflex (AWR) scores. Heterotypic intermittent stress (HIS) sham group showed a significant increase in AWR scores compared to control sham group under 20 mmHg and 40 mmHg distention pressures, while there was no significant difference in AWR scores between control and HIS groups after EA treatment. EA treatment at ST-36 point significantly decreased AWR scores in HIS rats, but had no effect on control rats under 20 mmHg and 40 mmHg pressures [Tukey post hoc test following two-way repeated measures analysis of variance (ANOVA)]. EA treatment significantly decreased AWR scores in both control and HIS rats under 60 mmHg and 80 mmHg pressures (two-way repeated measures ANOVA, n = 8 rats for each group; P < 0.05); B: Representative electromyographic (EMG) traces recorded immediately after termination of EA (left) or sham EA (right); C: Bar graph showing effects of EA treatment and sham EA on EMG recordings. The EMG was significantly decreased by EA treatment at pressure of 40 mmHg, 60 mmHg and 80 mmHg in stressed rats compared to sham EA groups (Tukey post hoc test following two-way repeated measures ANOVA, n = 6 rats for each group; ^aP < 0.05 vs HIS + sham group). CON: Control.