Objective: To reveal the mechanism of acupuncture in improving cerebral ischemia. Methods:A total of 120 Wistar rats were randomly divided into acupuncture (+ cerebral ischemia) group (n=36)

cerebral ischemia group (n=36)

sham operation group (n=36) and normal group (n=12). Cerebral ischemia was produced using middle cerebral artery occlusion (MCAo

thermocoagulation). Sixty minutes after MCAo

electroacupuncture of "Shuigou"(GV 26) and "Neiguan" (PC 6) was given to the rat by setting the parameters being frequency 4 ～10 Hz

0.4 V

dense sparse waves and duration of 5 min. Fluorescence dyeing of the vascular endothelial cells and white blood cell fluorescein tracing were applied for observing changes of the appearance

density and blood flow velocity of the micrangia of the cerebral pia mater 3 hr

6 hr and 24 hr after MCAo. All images were observed and recorded by microscope system of closed circuit TV and measured by computer image analyzer. Results: ① In normal group and sham operation group

the stained vascular endothelial cellular nuclei were very distinct

and the exudate staining was rather lighter. In cerebral ischemia group

the fluorescence staining of the vascular endothelial cells at different phases was lighter while that of the exudate was clearly denser

but in acupuncture group this state was obviously better; ② 3

6 and 24 hours after MACo

the density of capillaries in the cerebral ischemic region of cerebral ischemia group decreased remarkably while that of acupuncture group was significantly higher than that of cerebral ischemia group (P<0.01). ③ 3

6

24 hours after MCAo

the blood flow velocity of cerebral ischemia group became very slow

while that of acupuncture group was remarkably faster than that of ischemia group (P<0.01). Conclusion: Acupuncture can reduce ischemic injury of the vascular endothelium and improve the cerebral microcirculation effectively and immediately.