在电镜下，本实验观察到家兔急性心肌缺血区的微血管内皮细胞损伤严重，淤滞肿胀的红细胞形成血栓，造成微血管通路阻塞。经电针“内关”，心肌缺血区开放扩张的微血管数量明显增多，微血管内皮细胞的损伤减轻，红细胞不肿眼粘连，不形成血栓另外，微血管内皮细胞向心肌输送物质的功能增强，结果表明电针“内关”穴对缺血心肌的主要作用之一，是使心肌缺血区较多的微血管网开放，以改善心肌的缺血状况Endothelia of myocardial capillaries were studied with electron microscope during myocardial ischemia of rabbit. The endothelia were injured badly; some of swelling erythrocytes were deposited in the capillary lumen and stlcked together as thrombi after a ligature of the left ventricular branch of coronary artery. Following electroacupuncture (EA) at Neiguan (P6)

there were more dilated capillaries in thb area of myocardial ischemia. Neither lnjured capillaries nor the swelllng erythrocytes were found in EA group.The result suggests that one of effects of EA is to make more capillary networks open and enforce the transportion from the capillaries to the myocardium so that the myocardial microcirculation can be improved.