中文摘要：

目的：探讨穴位电刺激预处理对大鼠心肌超微结构和内源性保护物质活力水平的影响。方法：16只雄性大鼠随机分为3组，空白对照组、耐力训练组和训练加穴位电刺激预处理组，后两组分别进行耐力训练8周和训练加穴位电刺激预处理8周，取穴相当于人体的内关和足三里穴。分别采用透射电镜观察心肌超微结构和分光光度计法观测心肌组织中CAT、SOD和5＇-NT的活力水平。结果：心肌透射电镜超微结构显示，安静对照组肌纤维和线粒体形态结构正常；训练对照组可见线粒体局部损伤；训练加穴位电刺激预处理组线粒体无明显异常。SOD和5’-NT变化趋势较为一致。安静值较低，采用穴位电刺激预处理则活性水平有增高趋势。CAT则在训练后下降（P〈0．05），采用穴位电刺激预处理活性水平有所增高。结论：穴位电刺激预处理可通过激活心肌组织中内源性保护物质活力水平、减轻大负荷训练对心肌结构的损害来保护心肌组织，预防超负荷训练引起的过度疲劳。

英文摘要：

Objective To probe the effects of preconditioning via acupoint electricity stiroulation on rats myocardial ultrastructure and endogenous protective substances level. Methods 16 SD rats are divided into 3 groups at random. Do nothing with the first group and exert 8 weeks endurance training to the second group, use endurance training and acupoint electricity stimulation on third group with Neiguan （pc 6）and Zusanli（st 36）. Use transmission electron microscopy to observe myocardial ultrastructure and spectrophotometry to determinate the CAT. SOD and 5＇-NT level respectively. Results The morphology and structure of muscle fibre and mitochondrion in sedentary group is normal. Local damage of mitochondrion could be seen in endurance training group and the mitochondrion of the third group seems no obvious abnormal. The tendency of SOD and 5＇-NT is same. Lower when sedentary and increase in acupoint electricity stimulation preconditioning group. CAT also decrease after endurance training （p〈0.05） and increase in acupoint electricity stimulation preconditioning group. Conclusion The research indicated that preconditioning via acupoint electricity stimulation may decrease damage of myocardial ultrastructure and encourage endogenous protective substances level, therefore prevent heart from exercise-- induced-- fatigue.