Effects of electroacupuncture on blood-brain barrier after cerebral ischemia-reperfusion in rat

The effect of electroacupuncture (EA) on the blood-brain barrier (BBB) after cerebral ischemia-reperfusion (I-R) was investigated in rats. The dye Evans Blue (EB) was used as a tracer for assessing the disruption of BBB. Fluorescence quantification of EB was performed to explore the temporal pattern of permeability of BBB after the cerebral I-R with a fluorescence spectrophotometer (HITACHI 650-60). Furthermore, the morphology of BBB opening was detected under confocal laser scanning microscopy system. It was found that the BBB opening after cerebral I-R was biphasic. A rare scattered extravasation of EB was detected 2 hours after cerebral I-R. The EB extravasation reached its first peak at 6 h then decreased at 24 h and increased again at the time-point of 48h after cerebral I-R. EA can attenuate the disruption of BBB after cerebral I-R. EA could not only limit the area of extravasation of EB, but also reduce the concentration of extravasation of EB in the rat brain after cerebral I-R. The results indicated that one of the mechanisms of curative effect of EA on the cerebral ischemia might be due to its function of protecting the integrity of BBB.