Comparison of the effects of pretreatment with repeated electroacupuncture at GV20 and ST36 on fatigue in rats.

Objective: To investigate and compare the effects of electroacupuncture (EA) pretreatment at GV20 and ST36 on fatigue in rats.

Methods: Rats were randomly allocated into 4 groups: control, fatigue, fatigue+GV20 and fatigue+ST36. The last two groups received EA pretreatment at GV20 or ST36 for 5 days before being maintained in cages filled with water to a height of 1.5 cm to establish an animal model of fatigue. We used the weight-loaded forced swimming test and open-field test and measured 5-hydroxyindoleacetic acid (5-HIAA)/5-hydroxytryptamine (5-HT) ratios and serum levels of blood urea nitrogen (BUN), lactic dehydrogenase (LDH) and testosterone as behavioural and biochemical markers of fatigue in the rats.

Results: Compared with controls, rats in the (untreated) fatigue group exhibited reduced weight-loaded swimming times and total movement/distance in the open-field test, plus higher BUN/LDH and lower testosterone levels. Both EA pretreatment at GV20 and ST36 increased swimming times, and reduced serum BUN/LDH. EA pretreatment at GV20 (but not ST36) increased serum testosterone. The 5-HIAA/5-HT ratios in four brain regions were decreased in the fatigue+GV20 group compared with the fatigue group (p<0.05). By contrast, 5-HIAA/5-HT ratios in striatum and hypothalamus (but not hippocampus or midbrain) were decreased in the fatigue+ST36 group compared with the fatigue group (p<0.05). Furthermore, only pretreatment at GV20 affected the results of the open-field test.

Conclusions: These results suggest that EA pretreatment had a positive effect on the prevention of fatigue. Pretreatment at GV20 had a greater anti-fatigue effect than pretreatment at ST36.