Effect of Electroacupuncture on Nerve Growth Factor Expression in Ischemic Cortex of Rats with Focal Cerebral Ischemia

[Objective] To observe the protective effect of acupuncture on ischemic cerebral damage. [Methods] SD rats were randomized into 2-week sham-operation (2W-SO) group (n=6) , 5-week sham-operation (5W-SO) group (n =6) , 2-week cerebral-ischemia (2W-CI) group (n-6) , 5-week cerebral-ischemia (5W-CI) group ( n = 6), 2W-CI + electroacupuncture (EA) group (n=6) and 5W-CI + EA group (n=6) . Except the sham-operation groups, cerebral ischemia was induced by heat-occlusion of middle cerebral artery in other groups. Changes of nerve growth factor (NGF) expression were monitored in ischemic cortex of rats with 2-week and 5-week ischemia by immunohistochemical method, and the effect of electroacupuncture (EA) was observed. [Results] Few NGF-positive cells were found in the ischemic cortex of sham-operation groups and the expression of NGF were obvious in cerebral ischemia groups as compared with the sham-operation groups ( P 0.01) . The number of NGF-positive cells decreased in 5W-CI group as compared with that in 2W-CI group (P 0.01). NGF expression increased in 2 W-CI+ E A group, the difference being significant as compared with those in 2W-SO group and 2W-CI group (P 0.01); NGF expression was decreasing in 5W-CI + EA group and was still obvious as compared with that in 5W-CI group (P 0.01) . [Conclusion] EA can increase the secretion and expression period of NGF in rats ischemic cortex, and this may be one of its protective mechanisms for ischemic cerebral damage.