经皮穴位电刺激对力竭运动大鼠海马、中脑5-HT及代谢产物含量影响的机制

目的：观察经皮穴位电刺激（TEAS）抗运动性疲劳的中枢5-HT机制。方法：27只雄性SD大鼠随机分为安静对照组、运动组和TEAS组，每组9组。应用跑台建立运动性疲劳模型，TEAS治疗选用大鼠“后三里”穴（相当于人类的“足三里”穴），刺激参数：连续波、频率2Hz、强度5mA、时间30min，左右交替，每日1次，连续治疗7d。力竭运动后，记录力竭运动时间；用乳酸氧化酶法测定血浆乳酸含量；高效液相－电化学法（HPLC-ECD）测定脑内5-HT、5-HIAA含量。 结果：TEAS组力竭运动时间显著长于运动组（P<0.05）；运动组血浆乳酸含量显著高于安静对照组和TEAS组（P<0.05）；各组间海马和中脑5-HT含量比较差异无显著性（P>0.05），但TEAS组大鼠海马5-HIAA含量明显高于安静对照组（P<0.01），运动组大鼠中脑5-HT/5-HIAA比值显著高于TEAS组（P<0.01）和安静对照组（P<0.05）。 结论：促进海马、中脑5-HT代谢速率可能是TEAS抗运动性疲劳的中枢机制之一。

The mechanism of transcutaneous electrical acupoint stimulation on hippocampal and mesencephalic 5-HT and 5-HIAA contents in rats with exhaustive exercises

Objective: To investigate the central 5-HT mechanism of transcutaeous electrical stimulation(TEAS) in treating exercises-inducing fatigue in rats. Method: Twenty-seven adult male SD rats were randomly divided into normal group, model group and TEAS group, 9 rats in each group. The rat model of exercises-inducing fatigue was established by treadmill running. TEAS (continuous wave, 2Hz, 5mA) was applied to unilateral (left and right alternately)Zusanli (ST 36) acupoint for 30min, once daily for 7d. Time for inducing exhaustion were recorded on the 7th. Plasma lactate levels were measured by lactate oxidase method. Both 5-HT and 5-HIAA contents in brain tissue were detected by HPLC-ECD. Result: TEAS at point Zusanli(ST 36) not only significantly prolonged the time for inducing exhaustion(P<0.05), but also reduced plasma lactate levels markedly in rats with exercises-induced fatigue(P<0.05). The 5-HT contents in hippocampus and mesencephalon showed no statistically significant difference among all the observed groups(P>0.05). However, compared with normal group, hippocampal 5-HIAA contents in TEAS group increased significantly(P<0.01), while mesencephalic 5-HT/5-HIAA ratios in model group were higher markedly than those in TEAS group(P<0.01) and normal group(P<0.05). Conclusion: This study indicates that TEAS may postpone exercises-inducing fatigue by accelerating the metabolism of 5-HT in hippocampus and mesencephalon.